The Pirates are the last undefeated team, but history suggests that's a very good thing

With a nice clean record of 4-0, the Pirates are currently the last undefeated team in baseball. While they almost certainly will not go 162-0 this season, their hot start must be an encouraging sign for Buccos fans... right?

We were curious about how the last undefeated team in an MLB season actually fares over the rest of the year, so we tallied up some facts and figures for the last 24 seasons, going back to 1994 (the start of the Wild Card era).
To be clear, there were a few years where multiple teams tied for the most undefeated games to start a season, so we chose the team which literally stayed undefeated the longest. For instance, in 1995 the Cubs and Rockies both lost their first game on April 30th after starting the season 4-0. However, the Rockies game ended at 4:40 ET, while Cubs game ended at 5:36 ET, therefore the Cubs were the last remaining undefeated team. Silly? Yes. Still interesting? Also yes.
Here's what we found:

The average winning percentage for the last undefeated team is .537, which works out to a record of 87-75.
Of the 24 teams to hold the title, eight have won their division, seven have finished second, five have finished third, three have finished, fourth and last season, the Orioles became the first team to finish fifth.
The '97 Orioles, who started the year 4-0, finished the season 98-64, the best record among these teams.
Two teams - the '12 D-backs and the '05 Brewers - finished their seasons at exactly .500.
Just four teams - the '04 Tigers, the '06 Brewers, the '08 Royals and the '17 Orioles - went from being the final undefeated to posting a record under .500. Pretty impressive.
Only 11 of the teams have gone on to make the Postseason in total, but five out of the last eight have made it to October.
The '10 Giants and the '15 Royals are the only two teams to go from being the final undefeated team to World Series Champs, though the '02 Giants and the '11 Rangers did at least make it to the Fall Classic.
It's a little early to say that this Pirates can pull off what the Giants and Royals did, but history does suggest that the last undefeated team is more likely to go on to have a winning season.