PP,

If you have a 29% strike rate for each selection then the chances of not getting a winner with a group of 2 selections is very close to 50%. The chance of having 5 outs (no winners in 5 groups of 2 selections) is approximately 3%. So 3 times out of 100 you will start a progression and not strike a winner after 5 bets(10 really). The chance of you having 20 outs is just over 1 in a million which is highly unlikely.