Tuesday was Mitch Keller’s best start in weeks, but Alex Stumpf still sees major warning signs. Keller allowed five runs, walked three and surrendered eight hard-hit balls while barely using the sinker that once unlocked his sweeper. OffBeat breaks down how a four-seam-heavy approach, reduced velocity and a shrinking arsenal have left the Pirates’ highest-paid pitcher searching for answers, making this a revealing look at what has gone wrong and why the fix matters so much.