The performance of the Chicago Cubs pitching staff has been very odd in 2017. The starters were very mediocre in the first half sporting a 4.66 ERA, 1.37 WHIP, 8.5 walk rate and a 1.33 HR/9. The second half has been a bit different as they currently are pitching to a 3.51 ERA, 1.16 WHIP, 7.0% walk rate and 1.24 HR/9. Their second-half improvement has been credited to Jake Arrieta and Kyle Hendricks returning to their recent form, John Lackey pitching a bit better and the addition of Jose Quintana to the mix. However, there still have been some issues in the rotation recently which includes the recent struggles of Jon Lester.

Lester (33) was signed before the 2014 season to be their ace of the staff, and it certainly has paid off his first two seasons in a Cubs uniform. This year has been very inconsistent for him, and his last few starts have not been too good. He has a 4.56 ERA and 1.344 WHIP in 169.2 innings which includes a 5.88 ERA in his last 13 starts. It is very unusual to see in a guy who has been one of the best left-handed starters this decade and people want answers to why this is happening.

Recent struggles

He was a Cy Young finalist last year with a 19-5 record, 2.44 ERA, 1.016 WHIP and 197 strikeouts. Not to mention, he was the co-NLCS MVP on the way to the World Championship as he pitched a 2.05 ERA in the 2016 postseason.

This year not only is he giving up more runs, but he is also laboring in all of his starts. In his last 13 games, he is averaging 5.2 innings per start and throwing roughly 94 pitches. This stat means that he is not going deep into ballgames and his pitch count climbs very early as he has struggled to put guys away efficiently like he normally can.

Regarding his command this year, he has an 8.1% walk rate which is the highest it has been in six years. Also, he has tied his career-high in home runs given up without the season ended yet. The command struggles factor into him having to throw more pitches, fall behind batters giving up more hits and thus not having efficient outings.

Causes of struggles

There are some theories about what is going on with him. One is that he is simply not 100% physically. Lester missed some time last month on the DL with shoulder fatigue, specifically his Lat muscle. While he and the Cubs say that he is fine with no problems, there is always speculation of lingering problems that Lester may suffer, but it is tough to know. There are also questions about his age and mileage on him and that it is catching up to him, but 33 does not seem like it would be the end of the road and the Cubs refuse to believe that.

One could also question if not having veteran David Ross anymore could affect the way he is adjusting to Willson Contreras behind home plate.

It was evident that Lester, who pitched on opening night, was having some trouble getting on the same page with the young Contreras. Lester has been around a while, and though adjusting to new catching can affect different pitchers, it is hard to believe these problems with another catcher can last much longer if it is indeed a factor. In the end, people can see what Lester is not doing effectively, but it is hard to tell why.

Why not to give up on him

As mentioned before, Lester has been one of the better pitchers in baseball the past decade. A career 3.35 ERA, 1.243 WHIP, 2,030 strikeout pitcher with three World Series rings and one of the best postseason track records of all time, the guy is a winner.

His postseason ERA of 2.63 and World Series ERA of 1.77 tells just how good he is in the most crucial games of the baseball season. When he has had struggles, he has learned and adjusted which should give no doubt that he will again.

This season may not have been ideal for Lester, but if he improves in October, then he will once again be one of the toughest pitchers to any opponent to face.