Built by a 15-year grinder · Used every night

THE SIMS
BUILD YOUR LINEUPS.
YOU CALL THE SHOTS.

Tell it your reads — your stacks, your locks, your fades — and every lineup gets built inside the simulations, where teammates rise and fall together the way baseball actually works. Most sim tools tell you to stop fiddling and trust the robot. This one hands you the wheel. Built for DraftKings MLB grinders.

Try It Free for 24 Hours → See How It Works

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100K
Simulations per slate
$39
Per month, everything included
FULL
Optimizer control
24H
Free trial, full access

NO GUESSING.
WATCH IT BUILD.

From slate to export-ready DraftKings lineups. This is the actual app — recorded live, no edits.

onlydfs.com/app

Build Your First Lineup Free →

SEE WHAT YOU GET.
BEFORE YOU COMMIT.

Player Projections — With a Range
onlydfs.com/app
Dylan Cease
P · TOR · $10,000 ▲$100 · Dome
21.6
CPT 32.4
CEIL
44.7
FLOOR
4.2
VAL
2.2
OWN
13%
Jacob Misiorowski
P · MIL · $10,500 ▲$400 · Dome
21.1
CPT 31.6
CEIL
39.1
FLOOR
7.6
VAL
2.0
OWN
13%
Shohei Ohtani
P · LAD · $10,700 ▲$4,200 · 70° 10mph
20.8
CPT 31.2
CEIL
34.0
FLOOR
18.9
VAL
1.9
OWN
13%
Matchup Analysis — Pitcher vs Hitter
onlydfs.com/app
FAVORABLE MATCHUPS
Cal Raleighvs McCullers Jr.+9.4%
Juan Sotovs Valdez+8.1%
Joey Ortizvs King+6.7%
Jonah Heimvs Liberatore+5.9%
Drew Romovs Lugo+4.8%
Ketel Martevs Rocker+3.6%
Leo Jiménezvs Richardson-9.1%
Austin Martinvs Meyer-7.7%
George Springervs Jax-6.3%
Jake Fraleyvs Cease-5.4%
Gabriel Morenovs Rocker-9.5%
Corey Seagervs Nelson-8.2%
Dashboard — Game Environment
onlydfs.com/app
Weather & Game Environment
MIAvsMIN
4.94.1
O/U 9
70° 9 mph
KCvsCHW
4.04.0
O/U 8
51° 8 mph
TBvsTOR
3.14.4
O/U 7.5
⌂ Dome
STLvsOAK
4.35.7
O/U 10
70° 9 mph
SDvsMIL
2.94.1
O/U 7
⌂ Dome
CHCvsATL
4.73.8
O/U 8.5
77° 7 mph

FOUR ENGINES.
ONE UNFAIR ADVANTAGE.

// Engine 01

PROJECTIONS WITH A RANGE

Every player gets a real range — a floor, a ceiling, and an expected score — instead of one number pretending it knows exactly how the night goes. Trained on real games and weighted for the matchup, the park, the weather, and where he hits in the order.

Floor / Ceiling Weather-Aware Matchup Context
// Engine 02

THE SLATE, 100,000 WAYS

The whole slate plays out 100,000 different ways before you build. When a team erupts in a sim, its hitters go off together — so the stacks you end up with come from games that actually blew up, not from a rule you set. Baseball the way it really happens: in bunches.

100K Outcomes Stacks That Boom Win Rates
// Engine 03

WHERE THE CROWD ISN'T

The tool flags the players who win in the sims but the crowd is sleeping on — and the popular names that win far less than their ownership says they should. A hitter in 15% of winning lineups but on just 6% of rosters is exactly how you beat a big field. The pros call that gap leverage. Find the quiet winners. Skip the chalk.

Low-Owned Winners Dodge the Chalk Smart Pivots
// Engine 04

A LINEUP FOR EVERY OUTCOME

A full portfolio of lineups that each cover a different way the night could break — not a pile of near-copies that all sink together. Real stack shapes (5-3, 4-4, 5-2-1, and more), your exposure caps and locks enforced across the whole set, and one-click CSV straight to DraftKings.

5 Stack Types Exposure Caps CSV Export

THE SIMS BUILD IT.
YOUR READ STEERS IT.

Plenty of tools simulate the slate. But the sims usually just grade your lineups after they're built — and the few that build inside the sims tell you to stop touching the settings and trust the engine. DFS Only builds every lineup inside the sims, and lets your read steer the whole way.

// Old school

TRADITIONAL OPTIMIZERS

One average projection per player, jammed under the cap. You can set every rule you want — but stacks only happen because you forced them, and the math has no idea your hitters share a lineup. Total control, zero correlation.

Single Projection Forced Stacks No Correlation
// Half measure

SIM GRADERS

They build your lineups first — from ownership and stack rules — then run sims on the finished product to rank them. The sims show up after the work is done. They grade your lineups; they never built them.

Build First Sim After Rules-Based
// DFS Only

BUILT IN-SIM, STEERED BY YOU

Every lineup is built inside the sim worlds. When a team erupts in a simulation, that stack lands in your build because it happened — not because a rule forced it. And your locks, fades, stacks, and exposures steer all of it. The sim brings the correlation. You bring the read.

Built In-Sim You Steer It Real Correlation

AND THE TOOLS TO
CASH THE TICKET.

// Live tool

LATE SWAPS

A starter gets scratched an hour before first pitch. Instead of eating a zero, swap him out before his game locks — and re-optimize the open spots around the players already locked in. Salvage the slate instead of watching it burn.

React to Scratches Swap Before Lock Re-Optimize Live
// Built in

SLATE CHAT

A chat room for every slate, built right into the app. Talk pivots, breaking news, and bad beats with other grinders without leaving for Discord or juggling a second screen. It's all in one place.

Per-Slate Room Breaking News No Discord Needed
Top Leverage Plays — Sample Slate
PLAYEROWN%WIN%LEVERAGE
C. Carroll6.2%14.9%+8.7
J. Soto24.1%31.8%+7.7
A. Bregman9.8%16.1%+6.3
K. Tucker32.4%19.1%-13.3
A. Judge41.2%34.0%-7.2

EVERYONE KNOWS THE "BEST" PLAYS.
THAT'S NOT AN EDGE.

The field piles in at 30-40% ownership on chalk. You're not gaining anything by rostering the most popular player — you're just flipping a coin with bad odds.

Leverage scoring shows you which players appear in winning simulations far more often than the field rosters them. Positive leverage = underowned winner. Negative = the trap everyone's walking into.

This is the concept that separates grinders who cash from grinders who donate. Not picking the best players — picking the best players that nobody else has.

dfsonly — simulation engine
Loading slate: MLB Classic — May 12
Players loaded: 142 | Games: 8
Running 100,000 game simulations...
████████████████████████████████████████ 100%
Top leverage plays found:
  J. Soto      own 24.1%  win 31.8%  lev +7.7
  M. Betts     own 18.5%  win 26.2%  lev +7.7
  C. Carroll   own 6.2%  win 14.9%  lev +8.7
Overowned fades:
  K. Tucker    own 32.4%  win 19.1%  lev -13.3
Portfolio built: 40 lineups | avg pts: 148.3 | unique: 100%

BUILT BY A GRINDER.
TESTED WITH REAL MONEY.

DFS Only — 1st Place DraftKings Win
Real result · 1st place
DFS Only — 1st Place MLB $300 Dime Time Win $49.07
MLB Dime Time · 1st place & 3rd place
// The backstory
I SPENT 15 YEARS LOSING.
THEN I BUILT THIS.

I've been grinding DraftKings since the lobbies were small. I watched them explode into shark-infested waters, and for most of that time, I was the guy making the syndicates rich — relying on gut feeling and a spreadsheet held together by duct tape.

The realization that changed everything: the pros aren't predicting outcomes. They're running thousands of possible futures and betting on the patterns that emerge. A .300 hitter still gets out 70% of the time. If you're building one lineup based on the "most likely" outcome, you're already dead.

So I stopped trying to out-guess the experts and started building. I poured every late-swap panic, every slate-breaking bad beat, and every dollar of hard-earned tuition into creating the system I wished had existed when I started.

So I built the tool I always wanted: one that runs every lineup through the sims for real correlation, but never takes the controls out of my hands. My reads still drive it. I priced it at $39/mo — enough to keep it running, cheap enough that a grinder can actually use it every night.

Optimized for
DraftKings
Classic
Showdown
CSV Export

WE GRADE OUR
OWN HOMEWORK.

Every slate: stacks, plays, and fades posted to X before lock. Graded the next morning — hits and misses. Nothing gets deleted.

Before lock — posted 6:07 PM CT
📋 MLB SLATE BREAKDOWN — Jun 9 🔥 TOP STACKS: CHC · COL · OAK ✅ PLAYS: Willi Castro · Joc Pederson · Jared Young 🚫 FADES: Ronald Acuña Jr. · Spencer Steer · Jac Caglianone Sim ceiling, win rates + full card → onlydfs.com
Next morning — graded in public
📊 GRADING LAST NIGHT'S CARD CHC stack — 50 DK (#14) COL stack — 93 DK (#1) Willi Castro — 11 pts Jared Young — 0 pts Acuña fade — 0 pts. The field ate it. Model: 5/9 on the card · top plays avg 7 vs slate avg 7.3

The CHC stack missed. The Acuña fade hit. Both stay up. That's the whole policy — you can scroll the feed and count for yourself.

NOT BUILT BY A COMPANY.
BUILT BY A GUY WHO PLAYS.

No marketing department, no investor deck, no support ticket that routes to a stranger. It's one person who plays this slate every night, building the tool he wished existed — and running it with his own money before he ever asks for yours. When something breaks, you're talking to the guy who wrote it.

— Mike · builds it, plays it nightly · @abadmanmike

BUILT TO MAKE YOU MONEY,
NOT TAKE IT

Everything included — projections, sims, leverage, and the full optimizer. One plan, no upsells, no add-ons.

COMMON QUESTIONS

What is a Monte Carlo simulation?

Instead of using a single projection for each player, we generate 100,000 random game outcomes using correlated probability distributions. Players on the same team and in the same game are linked — when the game goes high-scoring, everyone benefits. This gives you a much more realistic picture of upside, floor, ceiling, and optimal lineups.

What does "leverage scoring" mean?

Leverage = simulation win rate minus projected ownership. If a player shows up in 15% of winning lineups but only 6% of the field rosters him, that's +9 leverage — a huge edge in GPPs. Negative leverage means the field is overvaluing a player relative to their actual win potential.

What platforms do you support?

Currently we support DraftKings Classic and Showdown contest formats for MLB. We're built specifically for DK's salary structures, roster rules, and scoring. FanDuel support is on the roadmap.

How are your projections generated?

We use gradient-boosted machine learning models trained on real MLB box scores. Features include rolling 7/14/30-day performance windows, opposing pitcher matchups, batting order position, Vegas implied runs, park factors, and weather conditions. Models are retrained as the season progresses.

Can I export lineups to DraftKings?

Yes — you can export your lineup portfolios as CSV files formatted for direct upload to DraftKings. Build your lineups, hit export, upload to DK. That's it.

Is this free to try?

Yes. Your first day is completely free — full access, no restrictions. After 24 hours it's $39/mo. You can cancel anytime before the trial ends and you won't be charged.

How is this different from sim tools like SaberSim or Stokastic?

Same family of approach, different philosophy. Some sim tools build lineups from ownership and stack rules first, then simulate the finished lineups to rank them — the sims grade, they don't build. Others construct from sims but discourage you from touching exposures and rules. DFS Only builds every lineup inside the sim worlds and keeps the full optimizer toolkit — exposures, locks, stack settings — in your hands. Same sim power; your read stays in the driver's seat.

Do I have to trust the sims blindly, or can I use my own reads?

Your reads drive it. Lock the players you believe in, fade the ones you don't, set your stacks and exposures — and the optimizer builds inside the sims around your calls. The simulations bring the correlation; you bring the slate read. That's the whole point.

THE SIMS BUILD IT.
YOU CALL THE SHOTS.

First day free. Full access. $39/mo after.

Run Tonight's Slate Free →

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