Expected return & house edge
Where 99.54% comes from, and what the 0.46% eats.
The long-run average
There are exactly 2,598,960 ways to deal five cards from a 52-card deck, and for every one of them a computer can enumerate all 32 ways to hold and every possible draw. A game's expected return (RTP) is the weighted average payout across all of it, assuming you make the best hold every time. For 9/6 Jacks or Better that average is 99.54% of everything wagered.
Every game on this site is honest about its number: returns run from 98.01% (7/5 Bonus Poker) to 99.73% (NSUD Deuces Wild). Every one of them is below 100% — the edge stays with the house everywhere, and perfect play only decides how small it gets.
What the 0.46% eats
Translate the edge into an hourly cost and it stops being abstract. On a quarter machine at max bet, each hand costs $1.25. Play 100 hands and you've wagered $125; the edge's expected take is less than a dollar.
Two honest caveats. First, that's the cost of perfect play — every mistake adds its own toll, which is what this site measures as strategy cost. Second, $0.58 is an average, not a prediction for your next 100 hands. Your actual result will land somewhere far from it, which is the subject of the next article.
Try it at the table
A low-edge baseline session: 9/6 Jacks or Better at the default $100 bankroll. Watch Statistics → expectation vs your actual net.