R
Running Nose II
Visionary
Silver Level
Phil Gordon was the first to coin "Rule of 2 and 4", where you multiplied our outs by 4 on the turn and by 2 on the river. Multiplying by 4 appears to be on the wane, probably because of the huge margins of error .Example : you have 15 outs and multiply these by 4 giving you a 605 chance to win. 605 equates to 0.67/1 against 2,07/1 true odds.
A Rule of 2 (and occasionally 4) evolved to overcome this problem.
You multiply your turn odds by 2. You multiply your river outs by 2 and multiply your turn outs by 4 if opponent goes all-in on the flop.
However even this has its shortcomings as will be shown
Outs X2 Odds to 1 True Turn odds True River odds
3 6% 15.67 14.67% 14.33%
6 12% 7.33 6.83 6.67
9 18% 4.55 4.22 4.11
12 24% 3.17 2.92 2.83
15 30% 2.33 2.13 2.07
18 36% 1.78 1.61 1.55
21 42% 1.38 1.24 1.19
A B C
Although on face value these figures appear acceptable, and they are after all approximate values, they do have their flaws.
Outs % Error on % Error on
Turn, A & B River, A & C
3 6.82 9.35
6 7.32 9.89
9 7.82 10.70
12 8.56 12.01
15 9.39 12.56
18 10.56 14.84
21 11.29 15.97
All figures are to two decimal places, rounded. column A is the percentages converted to a ratio.
If you are happy to use the rule of 2 with the errors shown, carry on. All I'm pointing out are the errors.
A Rule of 2 (and occasionally 4) evolved to overcome this problem.
You multiply your turn odds by 2. You multiply your river outs by 2 and multiply your turn outs by 4 if opponent goes all-in on the flop.
However even this has its shortcomings as will be shown
Outs X2 Odds to 1 True Turn odds True River odds
3 6% 15.67 14.67% 14.33%
6 12% 7.33 6.83 6.67
9 18% 4.55 4.22 4.11
12 24% 3.17 2.92 2.83
15 30% 2.33 2.13 2.07
18 36% 1.78 1.61 1.55
21 42% 1.38 1.24 1.19
A B C
Although on face value these figures appear acceptable, and they are after all approximate values, they do have their flaws.
Outs % Error on % Error on
Turn, A & B River, A & C
3 6.82 9.35
6 7.32 9.89
9 7.82 10.70
12 8.56 12.01
15 9.39 12.56
18 10.56 14.84
21 11.29 15.97
All figures are to two decimal places, rounded. column A is the percentages converted to a ratio.
If you are happy to use the rule of 2 with the errors shown, carry on. All I'm pointing out are the errors.