OpenFront Trade Route Chokepoint: Where to Place Your Port

Direct answer: place on the longest shared route, not the nearest water

OpenFront’s Trade Ship economy does not reward you for building the most Ports or for placing them closest to your neighbors. It rewards you for positioning a Port where your Trade Ships travel a long distance, because the Gold a completed voyage pays is a function of the distance the ship actually sailed, not of how many Ports you own or how close the partner sits. A single Port on a long, shared, connected water route will out-earn three Ports scattered over short local routes, and the gap widens as the long route gets longer. So the decision this guide answers is not “how many Ports do I build?” (a separate question the Port versus Factory guide and the how many Ports to build guide already cover). The decision here is narrower and more actionable: which water network and which route distance should my Port serve, and is the tile I am about to spend 125,000 Gold on actually the best chokepoint for that route?

The way to internalize the answer is to stop thinking of a Port as a store that produces Gold and start thinking of it as a terminal that receives Gold on behalf of a route. The route is the economic asset, and the Port is the place where that route’s completed voyages cash out. Two players with identical Port levels, identical partner relationships, and identical spawn cadence can earn wildly different totals because the routes their Ports serve are different lengths. The player whose Port sits on a 600-tile route out-earns the player whose Port sits on a 150-tile route even though neither does anything different in the moment of the build. That is the core reframe, and it is why the placement decision, not the purchase decision, is where the money is made or lost.

So the one-sentence decision rule is: before spending any Port Gold, identify the longest water route you can legally reach inside one connected water component, place the Port at the junction of the two longest routes you can defend, and hold that junction with a warship. Everything else in this guide, the version boundary, the Gold curve, the component graph, the scenarios, the failure modes, and the table, is elaboration of that one rule and the numbers that make it true at v0.34.22. Read the version boundary next, because every constant that the rule depends on is pinned to one specific tag, and if that tag moves the specific recommendations move with it even though the rule itself does not.

Version boundary: what v0.34.22 actually documents

This guide is written against the formal v0.34.22 tag of the upstream repository, checked on 2026-10-05. The engine behavior it relies on, all read from source at that tag: a Port runs a Trade Ship spawn trial every 10 ticks, and each Port level adds one additional trial; a spawn only succeeds if a valid destination exists; a valid destination must belong to another player, share the same connected water component as the Port, and allow trade in both directions; the Gold paid on arrival is computed from the water distance actually travelled through a sigmoid centred on 300 tiles; the global number of active Trade Ships slows new spawning around a midpoint near 330 ships; and the Port construction cost follows the ladder 125,000, then 250,000, then 500,000, then capped at 1,000,000. Those are the load-bearing numbers for every recommendation below. What this guide does not document, and must not be presented as version fact, is the exact historical trade-ship Gold cap before and after v29/v30 or the precise spawn-schedule change across those releases. The community reports a large single-ship value near 1.3 million in v29 dropping to a maximum around 412,000 in v30, and the v0.34.22 source shows the current distance-sigmoid Gold function, but the formal v0.34.x release notes do not spell out a per-version trade-ship cap, so this guide treats that transition as community-sourced and version-approximate rather than as a documented constant. The reason this matters is that a player reading an older walkthrough from the v29 era would see a single trade ship paying a million-plus Gold and would miscalculate how many completed arrivals are needed to repay a Port, so the cap transition is the single most common source of stale numbers in this exact topic.

If a balance patch later changes the Gold function’s midpoint, the saturation midpoint, or the Port cost ladder, every threshold in this guide needs a re-check against the new tag. The midpoint is the most sensitive of the three: moving the sigmoid from 300 to, say, 250 tiles would make short routes less bad and long routes less good, which would weaken the core chokepoint argument. The saturation midpoint is the second most sensitive: if it drops to 250 ships, then the late-game scenario in this guide, which assumes saturation near 330, would arrive earlier and the stacking-versus-spreading advice would need to shift toward earlier Factory conversion. The cost ladder is the least sensitive but still worth re-checking, because a doubled ladder would make the second Port level expensive enough that the “upgrade the chokepoint instead of adding a Port” advice could flip. So the version boundary is not a formality: it is the list of the three numbers that, if any of them moves, invalidate the specific recommendations and leave the underlying principle, favor distance over proximity and the chokepoint over scattered short routes, intact.

Read the route, not the Port count, before spending Gold

The first rule is to inspect the water network before you spend any Port Gold. A Port that has no reachable foreign destination is not an income source at all; it is a decorative tile that costs Gold and population to build and does nothing with it. To inspect a candidate location, ask three questions in order. First, is there a foreign Port, owned by another player, that sits in the same connected water component as the tile you are considering? If the water is separated by a landmass, an isthmus you cannot cross, or a barrier, then no legal route exists between that tile and that Port no matter how far or how close it is, and the Port will never trade with it. Second, is trade actually open in both directions, meaning neither side has issued an embargo or a stop-trading command? A route that looks geometrically perfect but is one embargo away from nothing is not a route you can bank on. Third, what is the real water distance, the path a Trade Ship will actually follow, rather than the straight-line distance the map makes it look like? The distance that matters is the travelled water path, and it is the input to the Gold function. The practical habit is to zoom out before the first Port, find the water component where foreign Ports cluster and where several long routes cross, and only then decide which single tile on that network is the best chokepoint. The Port versus Factory guide explains when a land Factory is the better first income, and this section is the moment you have already decided water income is worth it.

A useful way to make the three questions concrete is to write them down for the specific tile before the spend, in the order given. For the component question, the fastest field test is to click on a foreign Port and watch which water it is connected to: if your candidate tile and that Port light up as one connected body of water, the component question passes, and if they are in different bodies, it fails immediately and you should not spend on that tile for trade. For the open-trade question, the test is to check whether either side has an embargo or stop-trading active; a partner that is already at war with the player you want to trade with is a route that can vanish the moment their warship or their own diplomacy closes it, so the open-trade question is really a stability question, not just a current-state question. For the distance question, the test is to measure the actual water path a ship would follow, which is the path the engine uses, not the ruler distance across the map, because landmasses and the shape of the coast can make the travelled path much longer than the straight line. The habit of writing the three answers down for the exact tile, rather than for the region in general, is what separates a deliberate chokepoint decision from a placement made by proximity, and it is the cheapest insurance you can buy before committing 125,000 Gold.

The Gold curve is a distance sigmoid, and it punishes short routes

The economic engine is a sigmoid on route distance. At the v0.34.22 tag the Gold a completed Trade Ship pays is floor((75,000 / (1 + exp(-0.03 * (d - 300))) + 50 * d) * goldMultiplier), where d is the water distance travelled. The sigmoid part, the 75,000 term divided by a logistic centred on 300 tiles with a slope of 0.03, means that routes shorter than roughly 300 tiles sit on the flat, low part of the curve and pay disproportionately little, while routes longer than 300 tiles climb toward the high part of the curve and pay disproportionately more. The linear 50-per-tile term on top adds a steady distance bonus, so a long route gets both a large sigmoid payout and a large linear payout at once. A worked table at 1x Gold multiplier, evaluated from the formula, makes the gap concrete: a 100-tile route pays about 5,185 Gold, a 150-tile route about 8,324, a 300-tile route about 52,500, a 600-tile route about 104,990, and a 1,200-tile route about 134,999. That is roughly a twenty-fold swing between a 100-tile route and a 600-tile route, even though both consume exactly one spawn trial and one ship’s travel time. The consequence for placement is direct: a Port that can reach a 600-tile route is worth far more than a Port that can only reach 100-tile routes, and the reason is not that the 600-tile Port is “bigger” but that the engine pays it twenty times more per completed arrival. This is the whole quantitative case for choosing a long shared route over a cluster of short local routes, and it is the number that justifies the chokepoint placement that follows.

Water distance	Gold per arrival at 1x multiplier	Note
100 tiles	~5,185	Flat low part of the curve; poor
150 tiles	~8,324	Still below the 300-tile midpoint
300 tiles	~52,500	Midpoint of the sigmoid
600 tiles	~104,990	High part of the curve; strong
1,200 tiles	~134,999	Long route; sigmoid plus linear bonus

The practical reading is that route distance, not Port proximity, is what your Gold is computed from. Two Ports with the same level, the same spawn cadence, and the same partner will earn radically different amounts if one serves a 150-tile route and the other serves a 600-tile route, because the engine multiplies the far one’s payout by roughly an order of magnitude. This also means that the obvious player instinct, to place a Port as close as possible to the nearest friendly or allied Port so that ships travel less, is usually the wrong economic instinct. Shorter travel does save a little ship travel time, but it throws away the sigmoid’s reward for distance, which is the larger term. The only time a short route is the right call is when the long route is blocked, embargoed, or so heavily contested that ships cannot complete it; then a short safe route that actually completes beats a long route that never does. That tradeoff is the heart of the failure analysis later, but the default posture is to seek distance, defend it, and let the sigmoid do the work.

The water-component graph decides where a Port can earn at all

The water component is the hard eligibility gate, and it is the part of placement that people get wrong most often. A Trade Ship only ever travels between two Ports that share one connected water component. If your candidate Port and the foreign Port you want to trade with are in different water components, the engine will not pair them at all, and the Port earns zero from that partner no matter how good the tile looks. This is why a Port can look perfectly placed, sit on open water, have an allied Port visible on the map, and still produce nothing: the visible Port is in a different connected component, separated by land or by water the game treats as distinct. The component boundary is the real map you are choosing on, and it is coarser than the tile grid. In practice you should treat every connected body of water as one node in a graph, put your Port on the node that connects the most valuable foreign Ports, and accept that Ports on a different node cannot trade with it at all. This is also why island maps, archipelagos, and maps with large landmasses change the whole decision: on a map where the interesting foreign Ports are all in one big ocean component, a Port anywhere in that ocean can reach them, and the tiebreaker becomes route distance and chokepoint position. On a map split into several disconnected bays, a Port is locked into its bay’s trade and cannot reach the richer water next door, so the “best” Port is the one in the component that already holds the longest routes and the most foreign partners. The rule of thumb is to build the water-component graph in your head before the first spend: which component has the most foreign Ports, which component has the longest internal routes, and is my candidate tile inside that component? If the answer to the last question is no, the tile is not a chokepoint for anything you can legally reach.

There is a subtlety that trips up players who otherwise know this rule: the component boundary is decided by the water the engine connects, not by what looks continuous on the map at normal zoom. A narrow strait, a bridge of connected shallow tiles, or a short water gap can join two visually separate bodies into one component, and a one-tile land gap can split a visually continuous body into two. That means the component graph has to be read at a zoom where the connection tiles are visible, because the difference between “one component, long route, high value” and “two components, no legal route, zero value” can be a single tile. When you are unsure, the tiebreaker is to look for whether a Trade Ship can legally complete a round trip between your candidate tile and a foreign Port; if the engine will spawn and route a ship on that pair, the component question is settled, and if it will not, no amount of Port Gold or Port level will force the route. The component graph is also the reason two players on the same map can have completely different trade options even with the same number of Ports: the player whose Ports are distributed across several components is buying several distinct route pools, while the player whose Ports are all in one component is buying one pool and competing for it against everyone else on that water.

A single chokepoint beats three scattered short-route Ports

The pattern the community keeps rediscovering, and the one that follows directly from the distance sigmoid, is that one well-placed Port on a long shared route out-earns three Ports scattered over short local routes. The community phrasing, from the Reddit discussion on Port economics, is that a single Port plus a warship will get far more Gold than three Ports placed willy-nilly, and that you should zoom out and find where many boats are passing through and send your boats there even if it is a little far away. That is exactly the distance-sigmoid logic: the chokepoint is the tile where multiple players’ long routes are forced to converge, and a Port there can legally receive from several long routes at once, so one Port at the junction captures more long-route Gold than several Ports each serving one short route. The chokepoint is not simply the most traffic-heavy tile; it is the tile where the longest routes you can legally reach cross, and where a single Port plus a warship or two can hold the lane with the least exposure. To find it, look for the strait, the shared sea lane, or the open junction that sits between the richest foreign Ports, and ask which single tile on that lane can serve the most 300-plus-tile routes. Then confirm the cost: because Port levels follow the 125,000, 250,000, 500,000, 1,000,000 ladder, the first level on the chokepoint is cheap relative to the income it unlocks, and the second level doubles the trial count. The trade versus piracy guide covers the moment that same lane becomes a target worth capturing, which is usually the moment your chokepoint is strong enough that an enemy is willing to fight over it.

The decision procedure is to verify the component, choose the longest route you can defend, place the Port at the junction of the two longest routes, and then hold the lane with a warship inside repair range. If the route’s endpoint changes owners or the partner embargoes, the route’s value collapses even though the water did not change, and you must re-place or re-point the Port rather than keep feeding a dead route.

The reason the single-chokepoint pattern is robust rather than a lucky shape on a particular map is that it attacks both terms of the income equation at once. It picks the high part of the distance sigmoid, so each completed arrival pays a large amount, and it sits at a junction, so one Port’s spawn trials can be routed onto several long routes rather than one short one. A scattered set of short-route Ports does the opposite on both terms: each of its arrivals pays little because the routes are on the flat part of the curve, and its trials are spread across many routes that individually pay so little that the total per unit of Port Gold is low. The pattern also has a built-in safety property: a chokepoint Port is easier to defend than a set of exposed Ports, because a single warship can hold one junction while it cannot hold three separate short-route tiles. The community’s experience with this is consistent across the Reddit threads and the YouTube playthroughs, where the winning posture on a strait or a shared sea lane is always one well-defended junction rather than a scatter of small Ports, and the moment a player converts that junction into a capture lane is when the trade versus piracy guide decision comes into play.

Scenario one: a strait chokepoint opening against a quiet coastal route

Assume a 55-player free-for-all on an Africa-style map, and you are spawned near the mouth of a large river or a narrow strait that two or three foreign Ports rely on to reach open water. Your starting Gold is 150,000, you have one City at level 1, no Factory, and no warship. There are two candidate Port placements. Option A is a quiet coastal bay close to you, where the nearest foreign Port is only about 220 water tiles away and the route is safe because no enemy warship is nearby. Option B is the strait itself, where the foreign Ports you would serve sit about 560 water tiles away across open water, but an enemy warship of level 1 currently patrols the middle of that strait and a second foreign Port on the far side has not yet declared an alliance. You must choose which single 125,000 first-level Port to build, and the choice is a chokepoint-versus-safety choice, not a count choice.

The distance math says Option B is worth roughly six times more per arrival than Option A. At 1x Gold, the 220-tile route pays about 17,200 Gold per completed ship and the 560-tile route pays about 103,000 Gold per completed ship, so even before risk the strait route is the bigger prize. The risk adjustment is what makes it a real decision. The strait is contested, so assume an enemy warship intercepts and destroys roughly one ship in three before it can complete the lane, and assume the far-side Port might embargo you if you appear to be stealing its route. Under those assumptions, the strait route still pays about four-fifths of its gross per arrival on a net basis, which is still around five times the safe coastal route. The correct call, with one level-2 warship and enough Gold to repair it at your Port, is to build Option B at the strait chokepoint, keep the warship inside passive repair range, and hold the lane so the 560-tile route actually completes. The how many Ports to build guide explains why you should not also build a second Port in the same component here; the extra trial mostly moves the global fleet around rather than creating new income. The failure version of this scenario is building Option A first because it is safe and cheap, then finding that the strait was captured by another player and your quiet coastal route was worth a fraction of the chokepoint you never took. The counter to that failure is to treat the safe route as a fallback, not the plan, and to spend the first Port on the contested long route while you still have a warship to defend it.

Scenario two: a late saturated map and the stacking-versus-spreading choice

Assume a late free-for-all on a map with several large islands and one shared strait. The global active Trade Ship count is about 360, which is past the saturation midpoint near 330, so new spawning is already slowed and most Port Gold now redistributes the existing fleet rather than creating new ships. You already have one level-1 Port on the strait chokepoint, and a second Port at the far end of the same strait. A third foreign Port in a different component is reachable only through a long, exposed route. You have 400,000 Gold and one level-2 warship with about 1,100 health, and the question is whether to upgrade your existing strait Port from level 1 to level 2 (cost 250,000) or to build a brand-new third Port in the other component (also about 250,000 for the first level).

The saturation math says the third distant Port is the weak play here. At 360 active ships the global spawn is throttled, so a new Port mostly competes for the same fixed fleet, and the distant component adds a route you can defend less well because the warship must travel far to cover it. Upgrading the existing chokepoint Port from level 1 to level 2, by contrast, adds one more spawn trial every 10 ticks on a route that is already proven to complete, and because the strait route is already on the high part of the distance sigmoid, the extra trials land on high-value routes. The upgrade also shortens the decision: you are not opening a new lane that an enemy can contest, you are deepening a lane you already hold. The correct call is to upgrade the strait Port to level 2, keep the warship patrolling the middle of the strait, and only consider the third component later if the current lane’s endpoint changes owners or the saturation clears. The in-game Gold rates guide covers the land income you can run in parallel so that the Gold for the upgrade and the warship repair does not have to come only from trade. The failure version of this scenario is building the third Port on the exposed distant route, spending 250,000, and then losing a warship covering that lane, which removes the defense of the strait chokepoint that was already earning more. The counter is to resist the “more Ports is more income” reflex in the saturated late game and to spend on the lane that already completes, not on a new lane you have to fight to make safe.

Failure modes, countermeasures, mode and map adjustments, and the repeatable table

The most common failure is placing two or three Ports close together on the same short route. Because the Gold function depends on distance travelled, not on how many of your own Ports sit near the route, adding a Port next to another Port on the same 150-tile route does not multiply the 8,300 payout; it mostly spends 250,000 for another trial that competes for the same short-route income and reaches the local stacking penalties faster. The counter is to spread to a different water component or a genuinely longer route before you buy a second Port, and to remember that the Port versus Factory guide is the right place to ask whether the second income should be a Factory at all. A second failure is placing a Port in a water component that has no foreign Port, which turns the Port into a pure defensive tile that earns nothing; the counter is to check the component graph before the spend and to treat an isolated Port as a warship-repair anchor, not an income source. A third failure is stacking Port levels when the global fleet is already saturated, which buys trials that mostly redistribute the fixed fleet; the counter is to hold the upgrade and check the active ship count, and to spend that Gold on a warship or a Factory instead.

Map and mode adjust the threshold. On an archipelago with one big shared ocean, the chokepoint is the junction where the longest open-water routes cross, and you should use a distributed set of Ports plus a reserve warship rather than one giant stack. On a land-heavy map, a protected Factory and City cluster can beat an exposed Port even when the distance formula says the long route pays more, because the land income does not depend on a contested water lane. On a narrow strait, place the warship patrol where ships leave shoreline safety and the Port at the tile that serves the most long routes, and keep a defensive post over the land route to the Port so the enemy cannot simply storm the tile. In a team lobby, assign one player to watch the route, one to hold the escort, and one to convert Gold into land, so that nobody spends a second Port on the same lane the team already covers. Every 60 ticks, record five numbers: completed arrivals on your route, the completion rate of the lane, the distance to your nearest repair Port, the unspent defensive Gold, and whether the route’s endpoint owner is stable. Choose the chokepoint when the lane completes and the endpoint is stable; choose the safe short route when the lane is contested beyond your warship budget; choose a Factory when the water is too exposed and the land is defensible. That loop, with the distance table above, is the whole decision.

Observed situation	Default placement decision	Recheck after
300+ tile route, stable endpoint, no escort	Level-1 Port at the chokepoint	3 completed arrivals
600+ tile route, enemy warship on the lane	Port plus one escort, hold the lane	One escort sighting or 60 ticks
No foreign Port in the component	Skip the Port; spend on land or defense	Component change or ally port built
Global fleet above ~330, lane already completing	Upgrade existing Port, do not add a new one	Endpoint change or saturation drop
Lane endpoint changes owner or embargoes	Re-place or re-point the Port	New stable endpoint confirmed

Official sources and version boundary

Every rule and number in this guide traces to the formal v0.34.22 tag of the upstream OpenFrontIO repository, checked on 2026-10-05. The Port cost ladder, the distance-sigmoid Trade Ship Gold function, the 300-tile short-range midpoint, the 10-tick spawn trial, the same-water-component eligibility rule, and the 330-ship saturation midpoint are all read from source at that tag. The community-sourced material, including the Reddit threads on Port economics and the YouTube playthroughs on trade-lane and chokepoint control, is recorded in the research source pack and used to confirm the player-facing decisions and the Suez-style strait example; the v29/v30 trade-ship Gold cap transition is treated there as approximate and version-uncertain. When the next balance patch changes any of these constants, the thresholds and the worked scenarios in this guide must be re-audited against the new tag before they are trusted again. The trade versus piracy guide and the Port versus Factory guide are the natural next reads once the chokepoint is placed and the lane is held.

The community sources used for the cross-checks and the scenario framing are the three r/Openfront threads on trade and Port economics recorded in the source pack, accessed on 2026-10-05 through the pullpush.io archive: the “why does trade and money creation never make sense” thread, the “are ports now bad” thread discussing the v29/v30 cap change, and the “ports math” thread where the player works out the Gold-per-arrival and the single-warship-plus-Port pattern. The YouTube sources are the playthroughs and strategy videos that narrate the same chokepoint logic, accessed the same day, in particular the “I controlled the MOST VALUABLE trade route!” playthrough on a Suez/Nile bottleneck map, which is a concrete instance of exactly the strait-chokepoint pattern this guide recommends, and the “Ports and trade, a guide?” video that explains the Port and trade basics in plain terms. None of these sources is treated as version authority: where a number conflicts with the v0.34.22 source, the source wins, and where the source is silent, the community number is labelled approximate and the player is told to verify it in-game against the current live build. The split between what the source documents and what the community reports is what keeps this guide from importing a stale v29 number into a v0.34.22 recommendation, and it is the same split the version-boundary section applies to every threshold, so the two sections are deliberately written to point at each other.