Stokastic Sims Settings: 5 Dials, Only 2 Force A Re-Run

Most of the questions I get about the Stokastic Sims settings are not "which players are good." They're the ones a subscriber asked in our sim-tools support channel: how much should I actually move stack exposure, player exposure, and the ROI boosts, and when is leaving the defaults alone the smarter play? It is the right instinct, because the fastest way to break a good simulation is to override it with a hunch. Below is how I set the MLB DFS Sims settings for tournaments on DraftKings and FanDuel, what each control is really doing, and the short list of moments where deviating from the defaults improves your build instead of hurting it. If you have never run the tool end to end, start with how to use the MLB DFS Sims for the full workflow, then come back here to tune it. Pull up a live board of MLB DFS projections, ownership and stacks in the DataHub to follow along.

The Quick Answer

Leave the Stokastic Sims defaults alone unless you can say out loud what your change tells the model that it does not already know. Of the five dials in this guide, only the two on the field side (pool size, and the projection and ownership inputs the field is built from) force a re-run; exposure caps, stack exposure, and ROI boosts are finishing tweaks you apply at the end and re-favorite, moving two or three players a slate in small nudges. The five-dial cheat sheet, the boost arrow most people click in the wrong place, the real before-and-after numbers from our exposure walkthrough, and a 150-entry MLB worked example are all below.

Watch: Adjusting Exposure With ROI Boosts And Caps

Before the dials, here is the tool doing the work: a short walkthrough from our Sims channel that fades one player with a negative ROI boost, caps another, and forces a third up, with the exposure numbers moving on screen. The clip runs on the PGA Sims, and the controls are the same ones you use in MLB. Watch on YouTube.

What The Sims Are Doing Before You Touch A Setting

The mental model that makes every setting decision easier is this. The Stokastic Sims (the Contest Sims) build a large pool of lineups shaped like the contest you are entering, using projected ownership, so that pool doubles as the modeled tournament field, and then play the slate out tens of thousands of times. Every lineup comes back with a simulated ROI rank, which is its expected return across all of those imagined nights against the contest payout structure, not its projected score, and the builds you export are the top of that board. The distinction is the whole point: you are optimizing for win probability across thousands of outcomes, not for one best-guess total.

Here is what the tool surfaces when a run finishes, as we walked through on our MLB Sims ROI clip: a Contest Generator pool of 5,000 lineups (that pool is the simulated field), played against each other tens of thousands of times inside the GPP payout structure we had selected, 25% to first, then every lineup sorted by simulated ROI. Next to each lineup you get its projected points, total ownership, stack shape and teams (a 5-3 or a 5-2, and which clubs), plus how often it won the contest, finished top 10, and at least min-cashed. There is also a dupes column, and dupes are baked into the simulated ROI, because a lineup that wins first place while duplicated by other entries is less profitable than a unique one. On a big MLB main slate dupes rarely bite; in showdown they matter.

One scope note before the dials: the simulated ROI and the leverage math below are tournament (GPP) tools. For cash games (double-ups and 50/50s) you are only trying to beat about half the field, so you sort your pool by projection instead of simulated ROI and take the top builds off that sort. Everything that follows assumes you are building for GPPs; the cash version of the workflow is in how to use the Stokastic Sims for cash games.

Used a generic DFS optimizer before? The DFS exposure settings and boost controls will feel familiar, but they are doing something more specific here. In a single-point optimizer, an exposure cap just limits how often a name appears. In the Sims, your exposures and boosts change the pool that gets simulated, so a small nudge ripples through thousands of contests. That is exactly why the defaults are worth respecting: they are already tuned to the win-equity math. Your job is targeted intervention, not a full manual rebuild. For the deeper case on why simulation beats a static optimizer, see MLB DFS sims vs optimizers.

The one rule that governs every setting below: a change to a Sims setting is you telling the model something it does not already know. If you cannot say out loud what information your adjustment adds, do not make it. Adjust on information, never on instinct.

The Settings Cheat Sheet

The whole toolbox, in one place before we go dial by dial:

The rest of this guide is how far to move each of these, and how to keep your changes from quietly turning the simulation back into a lineup you built by feel. Notice the split in that last column: only the two dials that change the simulated field itself, pool size and the projection and ownership inputs, force a re-run. Everything else is a finishing tweak you apply at the end, then re-favorite. As our staff answered in the sim-tools support channel when a member asked whether he had to redo his tweaks after every projection update: projection updates and a different pool size mean re-run, because everything downstream depends on them; your own ROI boosts, caps, and stack filters do not, so make them once you are close to final.

Pool Size: Match The Simulated Field To Your Contest

The first dial to get right is pool size, and it is the one most people misread. Pool size is the size of the simulated field the Contest Generator builds to model the contest you are entering, not a cap on how many lineups you export. A 2,000 pool is a 2,000-entry room for your lineups to compete against; a 10,000 pool models a large-field tournament, and the board you read afterward is every lineup in that room ranked. The Sims play that field out tens of thousands of times and the tool surfaces the builds with the best simulated ROI against it.

Because pool size is the simulated field, the rule is realism, not size: match it to the contest you are actually playing. A small single-entry contest wants a small pool; a milly-maker wants a big one. A giant pool modeling a contest you never entered gives you worse lineups, not better ones, because it grades your builds against the wrong room. The same logic runs the Low Stakes to High Stakes slider next to it: pushed toward Low Stakes, weaker plays show up more often in the field, the soft-room realism of a cheap large-field GPP; pushed toward High Stakes, the field concentrates on the top plays, and a more concentrated field makes the sim want contrarian pivots. The staff advice for learning the machine is to keep the contest size fixed, run both extremes once, and watch how your top-play exposures move. Since pool size and the archetype are generation inputs, changing either forces a full re-run (the whole field regenerates), so set them before you build, not as a last-second tweak. For a small archetype, staff use a pool of roughly 500 to model a 250-to-500-entry high-stakes contest, and the huge cheap contests get the bigger presets; the full breakdown, including why the late-swap tool's preset shows 2,000 rather than 5,000, is in our Stokastic Sims pool size guide. (The Data + Sims and Sims MAX tiers let you build larger pools when a big-field contest actually calls for one.)

The one-line read: pool size describes the room you walked into, so pick the field that behaves like your real contest and re-run once. Do not reach for the biggest number out of habit before you finalize.

Field Ownership Vs Your Exposure: Two Different Dials

This is the setting people mix up most, so it gets its own section. There are two separate ownership concepts in the Sims and they do opposite jobs:

• Projected Field Ownership is the tool's estimate of how the rest of the field will roster each player. Boosting it changes the simulated opponents you are trying to beat.
• Your Pool Exposure is how often your own lineups use a player.

Here is the mistake our exposure walkthrough calls out by name, and it is the one I see most in support: people who want more or less of a player go into the pre-contest sims and click the up and down arrows in the Contest Generator. Those arrows change that player's projected ownership, meaning how often the simulated field rosters him. They do not change how much of him you get. If you want to move your own exposure, the place to do it is the Players tab after the run, with an ROI boost or a cap, which is the section after next.

You adjust field ownership to make the simulated field more realistic, and you adjust your exposure to shape your actual entries. Getting the field right matters because leverage is defined against it: a low-owned bat only pays off if the field really is light on him. So before you cap or boost anything in your own pool, sanity-check the projected ownership against your read. If a popular ace is going to be chalkier than the model shows, nudge the field ownership up first, re-run, and let the simulated leverage math re-solve around the corrected field. Ownership and leverage are the engine of GPP scoring; if that idea is new, our MLB DFS ownership projections guide covers it in full.

Player Exposure Caps: A Hard Ceiling, Not A Steering Wheel

The exposure cap is a hard ceiling on how often one player can appear in your pool, and that is all it is. The mistake is opening the tool and immediately hand-capping 20 players to match your gut. That throws away the win-equity solution you are paying for, and capping several players at once, especially at a multi-slot position like the two pitcher spots on DraftKings, can silently kill good lineup combinations the sim would otherwise have found.

How I actually use it:

• Default: let the Sims set your exposures from the simulated ROI. That is the calibrated answer.
• Cap To Stop Over-Concentration when you fire many lineups. In a large single-entry or 3-max GPP I let a top play run high, because concentrating in your best build is correct there. In a 150-max build, I set a hard cap on any single hitter (say 40%) so a bad night from one bat does not sink the whole pool.
• Want MORE Of A Player, Not Less? Don't go hunting for a "minimum" setting. The lever for more of a player is a positive ROI boost: give him one and re-favorite, and his lineups get favored up and his exposure climbs while the field stays realistic.

The cap is a scalpel for one player, not a way to reshape a pool. And because it is a finishing tweak, not a generation input, you apply it at the end and simply re-favorite, with no re-run required. Move in small steps: a 40% cap and a re-favorite will teach you more than yanking one from 70% to 20% in a single move. If your real goal is thinning a whole group of players out of your builds, the answer is boosts, not deletions, and how to control your player pool in the Stokastic Sims shows why deleting a player tears a hole in the simulated field.

Set the field first, then let the Sims do the building. Get pool size and ownership right, then read the simulated-ROI board and export the top builds instead of rebuilding lineups by hand. The Stokastic Sims live on the Data + Sims and Sims MAX tiers, and code SIMTUNE10 takes 10% off your first payment.

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Stack Exposure: The Highest-Leverage MLB Dial

Baseball is a stacking sport, so DFS stack exposure is the highest-leverage setting on this list. The Sims come pre-loaded with the stack shapes MLB DFS commonly uses (the 5-3 and 5-2 builds you can see labeled on the board in our MLB Sims clip), and the board shows you each lineup's stack type and teams so you can read the construction at a glance. Leave those shapes alone unless you disagree with the field's construction, not just its players.

When should you push a specific team's stack exposure above what the sim wants? Only for a correlated edge the model may underweight, and MLB gives you concrete ones:

• Weather. Wind blowing out at a hitter's park is a real, namable reason to want more of that game's bats. That is information the base projections can be slow to fully price, and our MLB DFS weather and late swap guide covers how to read it.
• Park. A middle-of-the-pack lineup in a top home-run park plays up; the same bats in a pitcher's park play down.
• The Opposing Arm. A team stacked against a fly-ball starter with home-run problems is a stack you can justify boosting.

Every reason on that list is a correlation argument, not "I like this team." Absent weather, park, or an opposing-pitcher edge, let the pre-loaded stack exposure ride, and lean on the Top Stacks Tool to see which teams the model and the field already favor before you override anything. For the full framework, our MLB DFS stacking guide pairs with this, and the same correlation logic drives the QB-receiver builds in NFL DFS stacking once football is in season. And remember cash and GPP want opposite postures here: cash leans on a tight core of the highest-floor bats, while large-field GPPs want more distinct stacks and more leverage. If you find yourself building one lineup for both, that is a different setup, not a different exposure number.

ROI And Player Boosts: The Scalpel, Not The Hammer

The Boost arrows (a positive or negative nudge on an individual player) are the most powerful and most abused control in the tool. Mechanically, a boost is simple: give a player a negative 10% ROI boost and every lineup that contains him has 10% ROI subtracted from it, so when you adjust favorites those lineups lose ground to the ones without him and your exposure falls. A positive boost does the reverse. A boost overrides what the simulation concluded, so every boost is a small bet that you know something the model does not.

This is what those moves actually did on screen in our exposure walkthrough, with the tool's own before-and-after exposures:

The row I want you to sit with is the first one. A single negative 10% boost cut that player's exposure by 18 points, not because he was banned, but because every build with him now competes at a disadvantage. A big swing from a small number is the whole argument for nudging rather than yanking. And if you ever want a clean slate, the tool has a Clear Boost control: press it, adjust favorites, and every ROI boost resets.

Used right, that is exactly when to reach for it: confirmed late news the projections have not caught, a batting-order bump, or a leverage read you are willing to stand behind. It is also the right lever when your disagreement is about a player's range rather than his median, a volatile bat you think has a livelier ceiling than the field expects. When you flatly disagree with our median on a player, the stronger move is to edit the projection itself and re-run, which re-grades every lineup off the new number; the trade-offs between the three levers are in Stokastic Sims ROI boost vs projection vs cap. Used wrong, boosting ten players by a lot turns your simulated ROI board back into the manual lineup you would have built anyway, which defeats the entire reason to simulate.

My guardrails for boosts:

1. Boost the exception, not the rule. Most slates I touch two or three players, tops.
2. Small nudges, then re-favorite. A boost is a finishing tweak, so you don't re-run the sim; you re-favorite and pull your lineups again. See what one boost does to the board before stacking another on top.
3. Wait for confirmed lineups. The single best time to boost or fade is once a batting order posts and a name moves up, out, or into a platoon. Late swap is the highest-value in-slate action there is, and our DFS late swap guide covers the mechanics; if a bat gets scratched, the boost you set this morning needs revisiting.

If you cannot name the edge a boost represents, that is your signal to set it back to zero and trust the sim.

Contest-Type Presets: One Slate, Different Dials

The same board wants different settings depending on which tournament you are entering. This is how I shift the posture by GPP type (cash is a separate build, covered right below the table).

The through-line: as the field gets bigger and the payout gets top-heavy, you model a bigger and softer room, widen exposure under a cap, add unique stacks, and lean into leverage. As the field shrinks, you model a smaller and sharper room and tighten around your best simulated builds. The Sims will do most of this for you once you have the field ownership and GPP type set correctly; the presets above are the manual overlay, not a replacement for the simulation. The same posture shift applies in football, where the NFL DFS Sims run the identical controls and the Milly Maker build is the many-entry extreme.

At 150 entries you will not vet every lineup, and our staff do not try to. As they explained in the sim-tools support channel, the many-entry check is a set of portfolio guardrails, not a lineup-by-lineup read: the pool's average projection, its minimum-projection lineup, your exposure to the highest-owned players (are you comfortable with it in either direction?), any huge leverage on a player you do not actually like, and any stack shapes you did not want. If one of those is off, fix it at the guardrail level with a cap or a boost, not one lineup at a time.

Cash games are the exception, not another preset. Double-ups and 50/50s only ask you to beat about half the field, so they are not a leverage-tuning exercise. The staff method is simple: build your pool as usual, but sort the output by projection instead of simulated ROI and take the top builds off that sort. My own reasoning for why that works is floor: the top of a projection sort is the safest build in the pool, and safe is what a half-the-field payout rewards. Exposure caps, stack boosts, and leverage plays are tournament tools; in cash, the confirmed lineup and the projection do the work.

A Quick Worked Example

Say it is a hitter-friendly MLB main slate and you are firing a 150-entry GPP. The projected field is piling onto the day's most expensive ace, a $10,600 arm the tool shows at 22% projected ownership. These numbers are a teaching example, not a live board. Here is the setting sequence I would run, in order:

Notice the order: only Step 1 changes the field, so it is the only step that re-runs; Steps 2 through 4 are finishing tweaks I apply at the end and re-favorite. The row I keep coming back to is Step 4. That $5,400 hitter at 6% projected ownership is the kind of leverage piece that can separate a big-field build: if he goes off in a windy park the field barely rostered him, my boosted lineups jump the pack, and the 40% cap on the chalk elsewhere means one cold bat cannot sink the pool. And remember the walkthrough table above: a 10-point boost moved a player's exposure by 18 points in one direction and about six in the other, so "modest" means a nudge, then a look at the board. Set the field, apply the tweaks, then I read the simulated-ROI board, where the tool surfaces the top builds by expected return, and export. The entire discipline is intervene where you have an edge, and let the Sims solve everything else.

The Bottom Line

The defaults in the Stokastic Sims are not a starting point to be overridden; they are a calibrated solution to a hard probability problem. The distinction that runs the whole workflow is field versus finish: pool size and the projection and ownership inputs shape the simulated field, so they are set up front and force a re-run, while exposure caps and ROI boosts go on at the very end, and you re-favorite instead of rebuilding. Remember how much a small finishing move does: one 10% boost swung a player's exposure by 18 points in the walkthrough, which is why nobody needs ten of them. Correct the field, match your pool size to the contest, cap for many-entry play, and boost only the two or three players where you have a real edge. For cash, set the leverage aside and build around projection, floor, and confirmed lineups instead. Move the dials with a reason, in small steps, and re-favorite between finishing tweaks. Do that and the tool works with you; override it on feel and you have just built lineups by hand with extra steps.

Ready To Tune Your Own Slate?

The Stokastic Sims build your MLB DFS lineup pool, simulate it against a modeled tournament field tens of thousands of times, and hand you the builds with the best simulated ROI, plus the exposure, stack, and ROI-boost controls covered above. They live on the Data + Sims and Sims MAX tiers, and code SIMTUNE10 takes 10% off your first payment.

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