Something strange is going on in professional football these days--the proliferation of the two-point conversion.
I've long held that teams should be going for two more often. As noted in the above article, in theory they are about equal--slightly less than half of two-point conversions are successful, and slightly less than all of regular extra points succeed, so the math is basically a wash. (It helps that getting an extra point is slightly harder than it used to be.) It's mostly just a strategic choice to make; being down late is usually a no-brainer to go for two.
This past weekend the Steelers attempted four (!) two-point conversions, an anomaly in a league where you might get four attempts across all teams on any given Sunday. Sadly, the Steelers didn't make any of theirs. (I assume; I haven't watched football for almost two years, Superbowl excluded. I'm still a little bitter about the league in general.)
Of course, math is math; I've always held that the first team that specializes in two-point conversions would have a pretty big advantage over anyone else. If you eke that success percentage up past 50%, even for a modest gain of, say, 53 or 54%, you'll probably earn enough expected points to get at least one extra win each season--and with the way the league is set up, that's not insignificant. Now, that advantage goes away the moment everyone else catches up (or at least practices enough to defend admirably against it) but it would be a good formula in the meantime.
For me, I'd ditch the extra point altogether, or at least make it a three point conversion, so almost all attempts are made. Extra points are boring; conversions are exciting. The way football is going, they need all the help they can get.