Nearly half of marriages fail, but not half of all first marriages. A simple example to illustrate: consider a sample of 4 happily married men and one guy with 4 ex wives. Half of the marriages failed, but 4/5 guys are happily married.

If you want to avoid divorce, don't marry a divorcee.

Incidentally, while divorce == FAIL, unhappy marriage == EPIC FAIL. But I guess the latter is hard to measure, so lets just focus on the former.