About NegativeEV
The goal of NegativeEV is not to make you rich from gambling. It's to keep you from going broke.
Written by Jesse, NegativeEV. Last updated 12 August 2026.
So many sites or people will try to sell you their picks or parlays.
"Just tail my plays, and you too can drive a lamborghini."
What a joke.
I joined one of these communities once. I spent 4 months paying for the privilege to lose money, blindly betting each play, believing that they had done their research and had a proven system, some sort of software that they backtested all of their picks against.
I was obviously wrong. I doubt any of these "cappers" has a system of more than just an Excel sheet. I know this because I'm a professional software developer who just spent a year building the prediction and simulation engine that drives this site. Beating the books is hard. Anyone who says they can do it is lying or believes variance is only that thing that happens when they lose.
NegativeEV exposes these people. It uses real data, years and years worth, and modern machine learning algorithms (yes, some AI) to predict every play of every game, start to finish, thousands of times. From a technology and architecture perspective, it's as good as it gets. If someone claims they can beat NegativeEV, then they either have superior technology (unlikely) or they're lying. Ask to see their proof. I certainly have mine.
So next time you're scrolling X and see a parlay with a "Who's tailing?" above it, take a screenshot and run it through here. You might be surprised how much money you save yourself.
Check a bet now
Open the checker: https://negativeev.com/
More about NegativeEV
- Research (measurements on real betting markets): https://negativeev.com/research
- How it works: https://negativeev.com/about/how-it-works
- How the simulator got built: https://negativeev.com/about/building-the-simulator
- How the simulator works: https://negativeev.com/about/how-the-simulator-works
- What expected value (EV) is: https://negativeev.com/about/expected-value
- What "negative EV" means: https://negativeev.com/about/negative-ev
- Are home run props a good bet: https://negativeev.com/about/home-run-props
- Are player prop bets a good bet: https://negativeev.com/about/player-props
- Are strikeout props a good bet: https://negativeev.com/about/strikeout-props
- Should you bet favorites or underdogs: https://negativeev.com/about/favorites-underdogs
- Are boosted bets actually a good deal: https://negativeev.com/about/boosts
- What the sportsbook's rake is: https://negativeev.com/about/vig
- Are moneyline bets a good bet: https://negativeev.com/about/moneyline
- How betting odds work: https://negativeev.com/about/odds
- What line shopping is: https://negativeev.com/about/line-shopping
- How sim-grading works: https://negativeev.com/about/sim-grading
- How accurate betting simulators are: https://negativeev.com/about/sim-accuracy
- How to check a parlay's EV: https://negativeev.com/about/parlay-ev
- Is betting the over a good bet: https://negativeev.com/about/totals
- Is the run line a good bet: https://negativeev.com/about/run-lines
- Is the run line better than the moneyline: https://negativeev.com/about/run-line-vs-moneyline
- Should you tail picks from X: https://negativeev.com/about/tailing-picks
- Are tennis match odds a good bet: https://negativeev.com/about/atp-match-odds
- Are parlays worth it: https://negativeev.com/about/parlays
- The X bot (@shoulditail): https://negativeev.com/about/x-bot
- For AI agents: https://negativeev.com/about/for-agents
