Splits before, after All-Star break tell story for White Sox, Cubs

It has been a season of split personalities for the Cubs and White Sox, who will play this weekend on the South Side.

The Sox are 26-28 (.481) since the All-Star break, showing a glimmer of rebuild hope after starting 33-62 (.347).

The Cubs entered their game Monday against the Diamondbacks at 32-24 (.571) since the break. That’s not far off their first half of 55-38 (.591), but they took a different route to get there.

Let’s look at some of the first-half/second-half splits that have the Cubs leading the National League Central and the Sox becoming more competitive:

Sox: Sox pitchers have a 4.49 ERA in the second half after a 4.93 ERA in the first. There also has been an offensive improvement from 4.04 runs per game to 4.26.

Their starting pitchers’ ERA has dropped from 5.21 to 4.53, and their strikeouts per nine innings have increased (6.5 to 7.4) while their walks have decreased (4.3 to 3.4).

Sox starters also have been better at stranding runners, with 71.6 percent left on base in the second half after 67.2 percent in the first. There’s some chance involved, just as there’s chance in a .264 batting average on balls in play in the second half after .272 in the first.

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Major strides have come from Carlos Rodon, who has a 2.81 post-break ERA after a 3.56 ERA before it. Oddly, Rodon has been striking out fewer batters (6.5 per nine innings after 7.3) and walking more (4.1 after 3.6). But BABiPs of .225 in the first half and .198 in the second suggest a correction is coming.

So do Rodon’s fielding-independent pitching numbers (5.03 in the first half, 4.50 in the second). He has been successful at getting pop-ups, with an 11.9 percent infield-fly percentage that’s the highest of his career. That includes 14.1 percent in the second half.

Cubs: The Cubs led the NL in offense in the first half, scoring 5.12 runs per game. Since the break, they’ve scored only 3.96 per game.

By weighted runs created plus, the good news has come from Anthony Rizzo, Ben Zobrist and Javy Baez.

With 100 signifying an average hitter, Rizzo has soared from 101 before the break to 163 after it, 13th in the majors. Zobrist, who was at 118 pre-break, is at 143 after, and Baez has been outstanding throughout a breakthrough season with 132 before the break and 133 after it.

Kris Bryant, who is at 108 after 131 in the first half, is the only other Cubs player above 100 in the second half. That’s subpar compared with his career 141 and in part reflects a fall-off to 11 home runs after 26, 39 and 29 in his first three seasons.

There have been major second-half shortfalls. Albert Almora Jr. has followed 114 in the first half with 46, Ian Happ 122 with 70, Willson Contreras 122 with 80 and Addison Russell 100 with 29. Russell’s wRC+ is the fifth-weakest of 292 players with at least 100 plate appearances since the break.

Having that much below-average offense has made runs difficult to come by. And with the all-Chicago series coming up, the Cubs have been outscored 227-222 in the second half — not as much better than the Sox’ 262-230 deficit as Cubs fans would hope.