Beat it on my first try, like all pitching challenges it is incredibly easy if you know how to game the pitching.
4SFB: Only ever throw up and in to both LHH and RHH. No other location.
CT: Throw inside to righties, pretty much never throw it to lefties.
CH: Throw either low and away or low and in to righties. Never throw to lefties.
CB: Down and in to righties, down and away to lefties.
2SBF: Up and in to lefties, pretty much never throw it to righties.
No, it doesn't make sense with actual real life pitching. But if you do only what I've laid out above, you'll get 14K's easily and most likely not a single hit along the way. You might think you've thrown a certain pitch in a certain spot too many times and the CPU will get wise but no, it never does. It just has certain pitches in certain spots SDS has decided are "bad" pitches that the CPU will punish even if they're great in real life (painting the low outside corner with a FB is a great example: fantastic pitch in MLB, but The Show CPU's crush it constantly). Just stick to the above and 14 K's is a walk in the park.