A few days ago, Tom McCarthy offered this explanation as Kevin Frandsen was coming to bat.
It's been a completely different year for him -- he's just not hitting like he was last year. He came up and he had tons of hits. This year has been much more of a struggle for him.
Presumably the main reason for this comment was Frandsen's batting average:
.338 - last year
.239 - this year (might have been .238 at that point, but his stats haven't changed much)
How to explain then that the advanced stats tell a very different story?
The more mainstream OPS and OPS+:
.834 / 123 - last year
.798 / 117 - this year
Or the more advanced and accurate wOBA and wRC+:
.362 / 127 - last year
.356 / 128 - this year
Both of these more comprehensive stats say that Frandsen is hitting, overall, about as well as he did last year. So how can this be? Not surprisingly, the answer lies in two areas that batting average completely ignores: walks/HBPs, and power.
Frandsen is walking at more than twice the rate he did last year.
4.3% - last year (6.7% incl. HBPs)
8.9% - this year (16.1% incl. HBPs)
The walks alone add about 46 points to his OBP, and HBPs add an additional 48 points or so. In the end, he's getting on base at nearly the same rate as in 2012:
.383 - last year
.364 - this year
He's also hitting with much more power so far. This is his ISO, i.e. isolated power (also called isolated slugging percentage), which is simply the difference between slugging percentage and batting average and represents the extra bases reached per at bat:
.113 - last year (23% of his hits were for extra bases)
.196 - this year (45% of his hits have been for extra bases)
He's getting fewer hits, but because he's getting more bases per hit, his total bases per at bat (i.e. slugging percentage) is about the same as last year:
.451 - last year
.434 - this year
He won't be able to keep up the higher power level, which is mostly a result of his 2 home runs. He has hit only 6 fly balls, and 2 of them have landed in the seats, and that 33% rate is going to come way down. On the other hand his BABIP (which was .366 last year) is only .243, and that will likely rise, leading to more singles going forward than he has gotten so far this year.
But setting aside whether what he's doing is sustainable or not, the bottom line is that he has been as productive so far this year as he was in 2012.
Thank you Tom for the useful illustration of why batting average is woefully inadequate as a single measure of a hitter's performance.
Frandsen at baseball-reference.com
Frandsen at fangraphs.com