That may be an unexpected reaction. After all, the White Sox do call Guaranteed Rate Field home, a ballpark considered one of the more home-run-friendly in baseball thanks to its having finished four of the past five seasons ranked among the top 10 in that department on our Park Factors page. However, you should consider this to be a bargain-shopping opportunity. For Keuchel, once you get past the perception of the stadium, Chicago is a sneaky-good partnership.
Keuchel, at this stage of his career, is more of a matchups-oriented pitcher than the Cy Young winner he was in 2015. In the four seasons since that honor was bestowed on the pitcher, his 19.4% strikeout rate ranked 114th out of the 159 pitchers who made 50-plus starts during that time span. His 59.4% ground-ball rate ranked third-highest and his 87.7 mph average exit velocity ranked 38th. This all hints at a pitcher more reliant upon hitting his spots, minimizing hard contact and, preferably, inducing hitters to hit the ball on the ground in order to succeed. Yes, he has always been that kind of hurler, but Keuchel had become increasingly so as he reached his 30s.
Couple his signing with that of new teammate and catcher Yasmani Grandal, though, and you just might have something. Grandal, for those unfamiliar with the backstop, is one of the game's best pitch framers. His 1,016 strikes framed (meaning pitches that had less than a 25% chance of being called strikes) over the past five seasons are 175 more than any other catcher in baseball. Grandal's 19.6 Framed Runs Above Average in 2019 (per our internal pitch-tracking tool) was second-best, behind only Austin Hedges' 26.1.
Yes, catcher framing is something that often gets exaggerated. It typically doesn't vault a starter pitcher from, say, the top-75 to the top-25 tier in fantasy terms all on its own. However, we're talking about an elite partnership once Keuchel's strengths are brought into the discussion. The left-hander has been one of the most likely pitchers to get favorable calls on close pitches, with 206 framed strikes over the past five seasons (second only to Jon Lester's 218) and 3.2 Framed Runs Above Average in his 19-start 2019, 16th-best among the 177 pitchers who made double-digit starts. In other words, expect to see a lot of corner-painting artistry in Chicago, and that might be enough to vault Keuchel up a few spots in the pitching rankings on its own.
Then there's this added plus: Keuchel is moving to baseball's lightest-hitting division. The White Sox's quartet of competition consists mostly of either small-market or rebuilding lineups, all with a high likelihood of repeating their run-production numbers of 2019. The American League Central was the worst of baseball's six divisions in terms of runs per game (4.57) and home-run rate (3.3% of trips to the plate) -- and neither competition was especially close. It's also possible that one of the division's top players from 2019 in terms of offensive Wins Above Replacement, Francisco Lindor (3.7), might also be traded before 2020's first pitch is thrown. Keuchel picked a destination that should maximize his matchup-seeking fantasy potential.
Again, Keuchel shouldn't be expected to revert to his Cy Young form, but there are enough positives to bump him up five spots in my SP rankings, earning him a place in the top 50. There's no question he should be drafted in the mid-to-late rounds of your mixed league.