This time of year, you need to look beyond the core statistics to determine true performance. Last June, I tagged Jorge de la Rosa as a pitcher primed for a turnaround. At the time, he was 2-7 with a 5.81 ERA. He finished 16-9 with a 4.38 ERA. I also predicted two arbitration eligible starters would head in opposite directions.
This year, Randy Wells is a candidate for a huge turnaround. His mainstream stats don’t look good (3-5, 5.15 ERA). But a pitcher’s actual performance is better evaluated with advanced metrics, especially in timeframes of less than half a season.
Wells has struck out batters more often than he did last season, when he went 12-10 with a 3.05 ERA. He has also given up home runs and walks less often than in 2009. The problem has been his high batting average on balls in play. His .359 BABIP is 65 points higher than last season. While he has allowed more line drives, this also shows that he has experienced some bad luck and/or poor defense behind him. A low left on base percentage demonstrates that Wells’ hits allowed have been poorly timed. Neither trend should hold up for the entire season, so expect his ERA to improve.
The disconnect between core statistics and advanced metrics isn’t always this great, but it always exists to some extent. Knowing this can not only build value, but it helps predict future performance as well.