The gap concept says you need a stronger hand to call a raise than you need to open first. If you are asking what is the gap concept in poker, that is the core answer: opening can win immediately, calling cannot.
Bot example:
Your bot might open K-J suited from the cutoff if everyone folds to it. But if a tight UTG player opens first, calling with K-J suited is much worse. Their range is stronger, you have less fold equity, and you are often dominated by A-K, A-J, K-Q, or big pairs.
How to encode it:
- Opening range: based on your position and players left behind.
- Calling range: opening range minus the dominated hands that perform badly against the raiser's range.
- 3-bet range: strongest value hands plus a few hands that work as bluffs against wide openers.
Most simple preflop bots miss this. They use one hand-strength threshold for every situation, then wonder why calls lose more than opens.