I wouldn’t trade anything of value for Hart. His first half is way over his head, and hitters who can be beaten that easily would scare me if I was looking to acquire them for a playoff run.
It is easy to see why one would hesitate on Hart. His 21 first-half home runs are only 3 off of his career-high and 9 more than he had last year. However, a closer look shows that his 2010 numbers are not that far ahead of his 2007 season. So this year’s production is not a total aberration. His OPS (.918) and wOBA (.390) both compare favorably to 2007 (.892, .380).
The only number that is really off the scale is his home run rate. This season, about 1 out of every 5 flyballs (18.8%) is leaving the park. That is well-above his previous career-high of 13.0% and more than twice the rate of 2009 (8.8%)
If the Rays do trade for Hart, maybe the lightning will remain in the bottle for the rest of the season. But even if his home run rate does regress, they can still expect decent production. But like Klaw said, just don’t give up anything of value.