One of poker’s golden rules is that players must act in turn. If they don’t, they could incur a penalty. Not only that, players who act out of turn — most notably by folding when action isn’t on them — is a good way to incur the wrath of your fellow players, especially when it’s likely to cost them money.

A glaring example of just why it’s so important to act in turn took place in the 2019 World Series of Poker $50,000-entry high-roller event, a tournament that drew 110 entrants and created a prize pool of nearly $5.3 million.

The hand in question took place in Level 22, with blinds at 100,000-200,000 plus an ante of 200,000. Sam Soverel was first to act and opened for 400,000. Dmitry Yurasov was next to act and shoved for 4.93 million holding Ad 10d.

Andrew Lichtenberger folded from the small blind. Ben Heath, who held Ah Qh in the big blind, asked for a count. Soverel broke down his stack to give an accurate count, and then Heath tossed in a time bank card, which allowed him an extra 30 seconds to decide on a course of action.

Soverel, who apparently wasn’t paying attention, must have mistaken Heath’s use of the time bank card as Heath mucking his hand, and Soverel wound up folding out of turn. Here’s why this was such a serious infraction.

The winner of the tournament was slated to take home just under $1.5 million, while the runner-up would receive $917,232. Meanwhile, the third- and fourth-place finishers would get $640,924 and $458,138, respectively. With a difference of more than $1 million between first and fourth place, there was serious money on the line.

In this spot, Heath had a decision to make that involved what his opponent, Soverel, would do behind him. When Soverel folded out of turn, he made Heath’s decision much easier. Heath no longer had to worry about Soverel over-shoving, which meant he could easily call Yurasov’s shove without further exposure. And that’s exactly what Heath did.

The board ran out Jd 5c Kh 3h 5h, and an angry Yurasov hit the rail. His frustration was understandable, as Soverel’s mistake took away any shot he had of scaring Heath out of the hand. Had Heath folded, it’s safe to assume Soverel would have as well, and Yurasov would have taken down the pot. Who knows how things would’ve played out from there.

Soverel apologized and admitted it was a big spot to make that mistake. Afterwards, Heath told PokerNews that things probably would have played out the same way despite the mistake.

“It was definitely going in either way,” Heath said, meaning that he wouldn’t have folded. “I think if I have a slightly worse hand, then it could become a bit interesting, but I genuinely think (Soverel) did it by mistake.”

The next time you’re about to fold out of turn, try to remember that your actions could potentially influence the integrity of the hand.