The Pirates have been hanging with us in the standings lately, but will they be able to hang with us all year? Some important stats say no. For instance we are crushing the Pirates in Run Differential. We lead all the majors pretty easily with 127 more runs scored than given up. Boston is in second with 91. Second in the NL is the Braves with 78. The Pirates are 8th, with just 46. The Reds are actually beating the Pirates with 63. Why is this important? Because Run Differential is a better predictor of future winning percentage than present winning percentage.
Based on Run Differential we can see the Tigers are very likely to win the AL Central even though they’re only 1 ½ games in front of the Indians. That’s because the Tigers, despite having 9th best winning percentage in the majors, have the third best Run Differential at 89. The Indians on the other hand, have the 10th best Run Differential at 25. The Tigers have scored .26 runs more than the Indians per game, and have given up .4 less runs per game. Expect the Tigers to have a much better winning percentage in the second half than the first. They’ve scored the 2nd most runs and given up the 13th least runs.
The Pirates are on the other side of variance. The Pirates are 1st in runs given up but 25th in runs scored. According to Baseball Prospectus based on runs scored and given up the Pirates average winning percentage is .560 rather than .602. That’s good for almost 4 less wins. The Cardinals are 3rd in runs scored and 3rd in runs given up. According to BP the average outcome of our run differential is .645, almost 3 wins better than our current record. Who would you give the best chance of winning more games? The average outcome of the Cardinals, Reds, and Pirates run differentials would be the Cardinals being over 5 games ahead of the Reds, and almost 8 games ahead of the Pirates.
Elsewhere around the league, Run Differential shows that the A’s are the favorite over the Rangers despite their close records. The A’s have a RD of 62 compared to the Rangers’ 23. Boston and Tampa Bay are the favorites in the east, with 91 and 60, compared to 27 for the Orioles, -2 for the Yankees (despite being 7 games over .500) and -12 for the Blue Jays. The Braves, unsurprisingly, are the only NL East team with a positive RD. The NL West should be close, with 9 RD for The Diamondback, 1 RD for the Rockies, and -18 for the Dodgers. With the Rockies getting back Tulo, and the Dodgers getting back a lot of injured players, it should be interesting.
But there isn’t only luck involved in run distribution and how many wins and losses it causes. There is also luck involved in how offensive production is distributed to cause runs. Fangraphs have two stats for this. wRC, which weights each player on the team’s hitting production to estimate how many runs should have been scored on average. They then have UBR, ultimate base running, which estimates how many runs should have been scored based on base running ability.
The Cardinals have been on the good side of luck on this, which means they’re scoring more runs than should be expected. That's not surprising given our insanely high RISP stats. While the Cards have scored 462 runs, they’re wRC is 434 with a -1.2 UBR score, meaning on average our stats would score 432.8 runs. The Pirates are actually scoring less runs than their stats imply, 369.2 compared to 357 actual runs scored.
Boston and Tampa Bay are actually scoring less runs that should be expected, with the Orioles, Yankees, and Blue Jays all scoring more than should be expected. While the A’s have outscored the Rangers 429 to 411, wRC and USB shows the A’s should have scored 414.6 runs and the Rangers should have scored 419.7. The Tigers, who are 2nd in wRC, should have scored 521 runs, but have only scored 477 runs. So expect their runs per game to be higher in the second half.
On the other side of the ball we can look at differences in ERA and FIP or what fangraphs calls E-F. This swings back into the Cardinal’s favor. The Pirates hold the biggest negative difference, as their ERA is 0.60 lower than FIP (3.08 to 3.68), meaning their pitching has given up over a half a run a game less than they should be expected to. The Cardinals are on the other side of the equation, with a FIP 12 points better than their ERA (3.40 to 3.28).
The team with the biggest positive difference of ERA and FIP? The Tigers, with a 3.86 ERA to 3.26 FIP. Outside of the Pirates and Tigers, not very many teams have big differences between the two stats. The Braves, Royals, Reds, and A’s are between -.34 and -.24, and the Rockies, Giants, Mariners, and Twins are between .36 and .23. The other 20 teams are all between .19 and -.18.
In conclusion, the Cardinals are winning less games than their Run Differential suggests, and the Pirates are winning more. The Cardinals are scoring more runs than their offensive production suggests and the Pirates are scoring a few less. The Pirates are giving up way less runs than their FIP suggests, and the Cardinals a few more. All and All I would say this gives the Cardinals a strong advantage going into the ASB. Also though don’t count the Reds out just yet. Pirates vs. Reds is the most likely NL wild card game scenario.
And for around the rest of the league? Well the most obvious conclusion is that the Tigers have had a really unlucky season so far. They’re scoring less runs than their offensive production implies, they’re giving up more runs than their FIP implies, and even taking how many runs they have scored and given up, they should have won a lot more games. Expect them to have a much stronger second half.
In the AL West expect the Rangers and the A’s to stay close. The A’s have a better Run Differential but have been scoring more runs and giving up less than their stats imply, while the Rangers have been scoring less runs and giving up more than their stats imply. A’s have the advantage but not by much.
In the AL East expect Boston to hold on and the Rays to play either the A’s or Rangers in the Wild Card game. The Yankees, Orioles, and Blue Jays stats can’t compare to the other two teams. In the NL West it seems to be settling around the Diamondbacks and the Dodgers, but don’t count out the Rockies completely yet. I would take the Dodgers based on the fact that they’re becoming a healthier team and Puig is now making a difference at the Major League level. And don’t expect any upsets in the AL Central or NL East.