What Is ABI in Poker? Average Buy-In Explained

ABI (Average Buy-In) is the mean entry fee across all tournaments played in a given period. It is the single number that best describes what stake level you are actually playing at - more accurately than any individual buy-in amount.

What ABI Tells You That Individual Buy-Ins Do Not

Most MTT players do not play a single fixed buy-in. They mix events – some $11 turbos, some $55 PKOs, occasional $109 Sundays. An individual buy-in tells you the cost of one tournament. ABI tells you the weighted average cost across your entire activity, which is the number that actually determines your bankroll requirements, your expected hourly earnings, and the stake level your results should be benchmarked against.

The formula is simple:

ABI = Total Buy-ins Invested / Total Tournaments Played

A player who plays 100 tournaments – 60 at $22, 30 at $55, and 10 at $109 – has invested $4,060 total. Their ABI is $40.60. Even though they occasionally play $109 events, their effective stake level is $40-$41.

ABI calculation example: 100 tournaments with mixed buy-ins resulting in an average buy-in of $40.60

 

ABI and Bankroll Management

ABI is the number you should use when calculating how many buy-ins your bankroll covers. If your bankroll is $4,000 and your ABI is $40, you have 100 buy-ins – exactly the standard minimum recommendation for MTT grinders. If your ABI drifts upward to $55 through shot-taking or mix changes, your same $4,000 bankroll now only covers 72 buy-ins – materially below the safe threshold.

This is why tracking ABI matters in practice. Players who take frequent shots at higher buy-in events without adjusting their bankroll mentally for the drift in ABI are underestimating their actual bankroll exposure. The 100 buy-in rule applies to ABI, not to your most common single buy-in.

ABI and Hourly Rate

ABI is also a key input for calculating expected hourly earnings. At the same ROI percentage, a higher ABI produces a higher absolute hourly rate. A player with 10% ROI and $22 ABI earns $2.20 expected profit per tournament. The same player with 10% ROI and $55 ABI earns $5.50 per tournament – 2.5x more, purely from playing at a higher average stake.

This relationship makes ABI a useful lever for improving hourly rate – but only when the move up is supported by both bankroll and a demonstrated ROI edge at the higher level. Moving ABI upward without the bankroll to support it is the fastest way to experience significant downswings that are difficult to recover from.

Common Mistakes with ABI

  • Ignoring ABI drift during series weeks. Playing higher buy-in events during festivals without tracking the impact on your ABI can silently push your effective stake level well above your bankroll’s safe range.
  • Benchmarking ROI against the wrong stake level. If your ABI is $40 but you compare your results to $22 player benchmarks, your performance looks inflated. Always benchmark against your actual ABI.
  • Not recalculating ABI after mix changes. If you add a new format or network that runs at higher buy-ins, your ABI changes immediately. Recalculate whenever your regular mix shifts significantly.