Originally Posted by statmanhal
The simple proportionality method suggested is okay as a first approximation. However, you should recognize that it assumes each combo has the same occurrence probability. In actuality, pairs have 6 possibilities. suited connectors 4 (Jd Td), unsuited connectors 12 (Jd Tc), two premium, or Ax - suited or unsuited, 16 ways (AQs, AQo).
So, if villain's 25 calling combos include all pairs and most suited connectors, then you would probably have to add in less that 15 additional combos since each added combo will likely have 16 possibilities.
Not sure if this is worth considering, tho.
Usually "combos" means what you're calling "possibilities". Pairs have 6 combos, etc. Of course you can weight combos - if he takes this line with AA 50% of the time then call it 3 combos instead of 6, or whatever.