He's just reading off the top of the Baseball-Reference Similarity Scores list. I think he wrote that stat? It's not the absolute worst comp I've heard recently (Rizzo to Ryan Howard). From age 21-24, Templeton put up bWAR of 3.4, 2.9, 4.2 and 4.4. Did he get hurt or something? He played in 80 games in his age 25 season, and then mysteriously lost his hit tool for the rest of his career. After this season, he should drop down Castro's comp list. There just aren't too many 21-year-old SS's with 200-hit seasons to compare him to.