I think baseball can have a paternity leave policy because the impact on
win-loss records of missing time is so much smaller than other leagues in the
course of an entire season. A baseball player that misses two games has been
absent for just over 1% of his games. In the NBA or NHL, a two-game absence
accounts for about 2.5%. In the NFL, the impact is obviously much greater
because of so few games. So for practical reasons, MLB teams are no worse off
for having the policy. The other leagues, especially the NFL, would do well to
put family first, but I understand them leaving it up to individual teams.