Brian McCann’s 24 homers in 2006 were the fourth-most in a season by a catcher younger than 23. The other three were two seasons by Bench and one by Earl Williams. Interestingly (or perhaps not) those occurred in consecutive seasons:

1 Johnny Bench 1970 45
2 Earl Williams 1971 33
3 Johnny Bench 1969 26

No other catcher that young has hit more than 18. Open thread.