chances your opponent won't have a pair on the flop or turn

[warlockjd]

Disclaimer: I am a probability ultranoob and will start answering many questions including this one (many incorrectly) in the hopes of improving. My goal is a super in-depth excel workbook with detailed preflop and postflop analyses to help me improve in superaggressive NL SH games.)

Opponent starts with pair (1/52 + 3/51) = 7.805%

Opponent does not start with pair = 1 - 7.805% = 92.195%

-Opponent pairs his nonpaired combination = 6/50 + 6/49 + 6/48 = 36.745 %

Opponent has a pocket pair or has flopped a pair 7.805% + (92.195% * 36.745%) = 41.682%


I hope this much is right, but do not know how to combine this with the assumptions that the flop contains no pair and/or that I fail to flop a pair.