St. Louis Cardinals second baseman JJ Wetherholt has compiled one of the strongest starts by a rookie at his position in recent decades. Through 56 games he leads all rookies with 2.5 fWAR.
Wetherholt has combined elite defense, a 123 wRC+ at the plate and seven stolen bases. He is on pace for a 7 fWAR season, which would surpass the mark set by any rookie second baseman in the last 100 years. Only Lou Klein of the 1943 Cardinals reached 6 fWAR in that span.