Two Down With Four to Play: The Math Behind the Press
From two down with four to play, an even match is lost about four times in five. A press over the same four holes is an even bet, unless you are outplayed.
Two down on the 15th tee feels fixable: win two holes and you are square. In an even match you lose from there about four times in five. A press changes what you are playing for over those last four holes, and the numbers show when it is worth calling.
What's Happening
Take two evenly matched players in a match, scored hole by hole. Give each a 35% chance to win any given hole, a 35% chance to lose it and a 30% chance to halve it, and treat every hole as independent. The probabilities below come from that model, which is simpler than real golf.
Run it from a few spots on the card:
One down with nine to play: you win the match about 28% of the time and at least halve it about 42%.
Two down with nine to play: you win about 16% and at least halve about 28%.
Two down with four to play: you win 6.6%, halve 12.6% and lose 80.7%.
Two down with two to play: your opponent is dormie, up by as many holes as are left. You cannot win. You halve only by winning both holes, 35% times 35%, about 12%.
80.7%
how often an even match is lost from two down with four to play, in this model.
More halving does not help. Make the match tighter, 25% win, 50% halve and 25% lose, and two down with four to play gets worse: you win 3.5% and at least halve 14.5%. More halves mean fewer holes that move, and from behind you need holes to move.
The Take
From two down with four to play, the original bet is mostly gone. Count a win as one unit and a loss as minus one, and that bet is worth about minus 0.74 units from the 15th tee.
A press does nothing for that bet. In the classic version, a press is a new bet, usually for the same stake, that runs from the hole it is called on to the end of the nine. Called on the 15th tee, it covers the last four holes and starts all square. In the same model, the press wins 38.5%, halves 23.0% and loses 38.5%. Its value is zero: a fresh coin flip sitting next to a bet you are probably losing.
In an even match, a press is a second, fair bet placed next to one you are probably losing.
That also tells you when to press. The numbers above assume an even match. If you are two down because your opponent is better today, the press inherits that edge. Give your opponent a 40% chance to win each hole and yourself 30%, and a four-hole press wins 29.4%, halves 22.4% and loses 48.2%, worth about minus 0.19 units. If you trail an even opponent on bad breaks, the press is a fair bet. If you trail a better player, it is a losing one.
Some groups make the press automatic: fall two down in a nine and the press starts on its own. It keeps the trailing player in a live bet for the rest of the nine, and in an even match it costs nobody anything. In an uneven match every automatic press is a bet the weaker player is more likely to lose.
The Proof
The same four holes, two bets:
The original bet from two down with four to play loses about four times in five. A press over the same holes starts all square and is an even bet.
The press bar is even only because the model is even. Against a better player, the same press starts as a losing bet.
The Cut
caddie.fun settles a paid Match Play round or Nassau hole by hole, so its press works on holes rather than as the separate match priced above: a press multiplies the money on the holes it covers, doubling it by default. The organizer chooses whether a press covers one hole or the rest of the nine, and can turn on auto-press at two or three down. The math holds hole by hole. In an even match, a press over the last four holes is worth nothing. Outplayed at 40% to 30% a hole, the same press costs you 0.4 of a hole's stake on average.