Once traded to the Cubs Wieck’s curveball became his primary secondary and that was more than likely the right call.
Brad Wieck throws his 90.6 mph to 96.6 mph fastball a whopping 77.4% of the time. He threw it in the zone 53.9% of the time and had a 12.1% swinging-strike rate. Of his 49 strikeouts, 37 came on his fastball and his BAA was .198. Wieck was tagged for four home runs in just 20 hits his fastball allowed, but his contact was spread fairly evenly (30.2 LD%, 31.7 GB%, and 38.1% FB%).
The slider was Wieck’s most problematic pitch. He threw it about the same amount (11.1%) as he threw his curveball (11.5%) despite much poorer results, allowing hitters to slash .400/.438/1.267 against the slider. He gave up the same number of home runs on his slider as he did with his fastball, even though he threw the slider 420 fewer times. With just three strikeouts and seven whiffs (10%), it would be advisable to reduce its usage even more, especially considering that hitters had a .658 wOBA and a 326 WRC+ on it.
A .100 BABIP enabled Wieck’s fastball to allow just a .105 average.
Wieck’s slider flashed a 16.7% whiff rate in 2018, but that came in just 30 uses.
Wieck used his changeup only two times, drawing a swing and miss on one of those.