Better is not what's being measured. The measure is contributions to wins. Boggs, being a good/great player contributed more by virtue of having played well for more games.

Think of it in terms of HN:

Let's say you and I both make the same number of comments and submissions per year. For 7 years each of your comments and submissions gets 100 karma. For 20 years each of mine gets 75 karma. On a per-comment/submission basis you contributed more, but I contributed more in my HN career.