Ok lets play through the whole scenario here, not just stopping after the first TD. We'll use your numbers (i don't know the real numbers but these are fine). When you go for 2, there's a 40% chance of being down 7, 60% chance of being down 9. In order for all of this to play out, we're going to assume that your defense gets a stop and you get the ball back and score a second TD. If that doesn't happen, you lose anyway, regardless of if you kicked or went for 2. Scenario A (go for 2)Go for 2 and get it (40%) + score second TD, kick PAT (100%) = tied. Go for 2 and fail (60%) + score second TD, kick PAT (100%) = lose game*Scenario B (PAT)Kick PAT (100%) + score second TD, go for 2, succeed (40%) = tiedKick PAT (100%) + score second TD, go for 2, fail (60%) = lose gameThese two situations have identical outcomes when you start throwing percentages around. However, I put an asterisk next to the lose game outcome in scenario A because if you know that you've failed, you now have 7 minutes to score twice. This means you know that maybe you have to onside kick, or maybe your scoring drive has to be very quick. However, in scenario B, you don't know that you need a second score until after your second TD, which could be at the end of the game. Look at the Houston game last night. If Houston hadn't made their 2 pt conversion, they would have only had all of 20 seconds or so to make a last ditch attempt at a score.