Did the Chicago Cubs really make a mistake not keeping Jake Arrieta?

Chicago Cubs: Did we dodge a bullet this time around?

Here’s a breakdown Jake Arrieta’s performance from 2016-2018. This obviously covers his final two years in Chicago and his first as a member of the Phillies. I decided comparing any player’s performance to Arrieta’s historic 2015 season was hardly a reasonable benchmark, so I omitted that year from the table below.

Jake Arrieta - By the Numbers

A breakdown of Jake Arrieta's performance, ranging from his Cy Young-winning 2015 campaign through 2018, his first season with the Philadelphia Phillies.

As you can see, his performance has been on a near-uniform decline across-the-board. His swinging strike rate has dropped nearly three percent since 2016, bottoming out last year at 7.8% – well below the league average of 9.5 percent.

When you factor in hard-hit rate (not shown in the table) – things really go sideways. In his Cy Young-winning 2015 season, Arrieta limited opponents to a 22.1 percent hard-hit rate. Last year? He clocked in at a staggering 36.2 percent mark.

Heading into Monday’s start at Wrigley Field, the bearded hurler has just 1,389 big league innings under his belt. But he’s not getting any younger and, simply put, the stuff just isn’t what it used to be. We haven’t seen him transition from overpowering ace to crafty veteran – at least not yet – in the way guys like Lester have in recent years.

Velocity and strikeout rate is down, contact rate is up and when you factor all that in, you can only reach one conclusion: things will likely to get worse, not better, as he heads into the back half of his 30s.