The additional amount that John wins at the end of the game on top of what he would have won had they shown their cards straight away (his ex-showdown winnings) is given at the bottom of each leaf of the decision tree. For example, if John has A and Tom has Q and decides to bluff (the path shown in red in the tree), then John will catch the bluff and win the £4 on the table, making a profit of £2. Had they shown their cards straight away, then John would have won the £2 on the table, making a profit of £1. Therefore John's ex-showdown winnings are £1.