JBJ was never platooned. He was benched, demoted and jerked from MLB to AAA, but never came close to an actual platoon with anybody.
He only started 26 games in 2013 (21 vs RHPs and 5 vs LHPs)
2014 starts: (team 113 to 49- 70% RHPs)
vs RHPs: 45 (68.2%)
vs LHPs: 21
Difference: -1.8% (NOT a platoon, since he faced a higher percent of RHPs than the team average)
2015 starts: (team116 to 46- 71.6%)
vs RHPs: 74 (66.7%)
vs LHPs: 37
Difference: -4.9% (Not a platoon at all- not even close. He faced about 5% less RHPs than the team average!)
2016 starts: (team 125 to 37- 77.2%)
vs RHPs: 119- 82.1%
vs LHPs: 36
Difference +4.9% (Maybe a slight platoon, but more like they gave him his normal days rest vs LHPs.)
2017 starts: (team 125 to 37- 77.2%)
vs RHPs: 104- 79.4%
vs LHPs: 27
Difference: +2.2% (Not a platoon)
There is zero evidense JBj was ever platooned.
Career splits:
.735 vs RHPs
.703 vs LHPs
He's probably got one of the closest career splits on the team.