TERM
Betting limits and account limiting
A limit is the maximum stake a bookmaker accepts on an outcome; account limiting is cutting that limit for a specific player, usually for betting surebets.
The limit depends on the event: for the final of a major tournament it is many times higher than for a CS2 second-division match. Account limiting is personal: a bookmaker that spots systematic surebet betting cuts the player's limit down to token amounts. This, not losing a bet, is the main risk for an arbitrage bettor.
Prediction markets don't set per-player limits: the constraint there is order book depth. More on limits in the article “Why Bookmakers Limit Arbitrage Bettors and What to Do”.
If the limit is below the calculated stake for a leg, calculate from the limit: the stake on the second leg equals limit × (1/k₂) / (1/k₁). Example: the calculation called for 4,940 ₽ at odds of 2.10, but the book accepted only 3,000 ₽. The second leg at 2.05 shrinks to 3,000 × 0.488 / 0.476 = 3,075 ₽, and the profit in rubles shrinks proportionally. Bet order: the book with the lower limit first, so you can size the second leg to the amount actually accepted.