The races are on:

Sizing up divisions, difference-makers.

It was a rich first half for home run hitters, starting pitchers and upward mobility.

It wasn’t all that good for those who crave in-season trades, thanks to the second wild-card spot and the logjam of contenders it creates.

The Arizona Diamondbacks, who were looking at 90-plus losses before the season began, were five games out in the wildcard race to begin the second half. They also had the ninth-best record in the National League.

But every team in the American League was within eight games. Such parity makes the St. Louis Cardinals’ .629 winning percentage even more impressive, not that it necessarily translates to the postseason.

Last year the San Francisco Giants and Kansas City Royals got to the World Series with fewer than 90 wins. That could happen again.

Twelve players have 20 homers. The overall major league batting average is up two points, the onbase-plus-slugging percentage (OPS) is up 10 and home runs are up incrementally, pausing the general trend of the 2000s.

And the Royals, Pittsburgh Pirates, Minnesota Twins, Chicago Cubs and Houston Astros have the second-, third-, sixth-, ninth- and 10th-best records in baseball. All of those teams have had at least one 90-loss season since 2011, and Houston lost 100plus games in three consecutive years (2011-13).

All this means anyone who wants to lay some money on the second half might consider investing in a lemonade stand instead.

Let’s try to make some sense of the divisions races and playoff picture:

DENNY MEDLEY, USA TODAY SPORTS The Royals, who stunned the baseball world by reaching the World Series last season, opened a substantial lead in the American League Central race.