A dead heat in betting is when two or more participants tie for a position in an event.
You back Paddy's Boy in the last at Kempton - it is heading for certain victory when out of nowhere comes Lucky Charm with a late run - they cross the line together and cannot be separated even after a photo finish. A dead heat is declared.
You have staked £10 on Paddy's Boy at 10/1 so what happens now?
The best way to think of it is that as two horses won the race and you only picked one, the stake has to be halved. You will get paid half your stake at the full odds so for the above bet your returns will be £55 (5 x 10 + 5 stake).
For three runners tied your stake is divided by three and so on.
If you bet on Player A but there is a tie with Player B, you will get paid on full odds, but the stake will be split between the number of players who drew. So your stake would be split in 2. If 3 players draw, your stake will be split in 3, etc.
For more information on Dead Heat in Golf click https://helpcenter.paddypower.com/app/answers/detail/p/6/a_id/136