I'm pro shiftbunt. Not all the time - nothing is ever true all the time, except maybe the statement "nothing is ever true all the time". But, throwing out some wild-ass guess numbers here, a great power hitter will homer in about 8% of his at bats (40 HRs in 500 ABs sounds about right for a great power hitter, no?). When the defense virtually concedes the entire left side of the field to a lefty power hitter, it's not unreasonable to assume he should be able to bunt successfully for a hit 60% of the time, I don't think. Hitting into the shift is hard. Let's say, without getting too fine about it, that our hypothetical lefty power hitter will get a base hit 12% of the time when he pulls the ball and it stays in the park. I don't take wOBA as gospel, but let's use it here. You get 0.89 credit for a single under wOBA and 2.10 credit for a home run. So if you accept the assumptions, bunting against the shift will get you (0.6)(0.89) = 0.534 wOBA credits on average. Swinging into the shift will give you (0.08)(2.10) + (0.12)(0.89) = 0.275 wOBA on average. So bunting into the shift looks like a much better strategy. Tons of caveats here. My guess that a bunt against the shift would be successful 60% of the time was a wild guess, and so was the 12% success rate for swinging into the shift. I didn't count the fact that the batter will get some doubles and triples swinging into the shift, too, though those wouldn't affect the numbers all that much. I'm implicitly assuming that the batter is equally likely to walk whether he bunts against the shift or swings into it. And I'm thinking about lefties here - even when there's a "shift" against righties, the first baseman isn't shifting much. And, of course, there are situations where the numbers get thrown out and swinging makes plenty of sense, like when your entire offense is named "Jay Bruce".