Phil Hughes needs a put-away pitch. Badly.

Over the years, Yankee fans have seen Hughes allow opposing batters to foul off pitch after pitch after pitch, until they either draw a walk or finally drive an offering that catches too much of the plate. This isn’t a case of our lying eyes telling us something that isn’t true. Hughes has generated a fouls/swing rate of 43.58% over his career, which is the highest rate among MLB starters who have thrown at least 1500 pitches in that time span. That’s just insane.

Part of the problem is an over-reliance on the fastball. Over his career, he has used that pitch 63% of the time overall and 60% of the time in 2-strike counts. That’s a microscopic difference, especially given that a fastball which averages 92.2 mph just isn’t going to blow away big league hitters on a regular basis. Without an effective breaking pitch, opposing hitters can sit on fastballs and fight them off until they get one that they can hit.

Hughes has tried to develop a good curveball, but it has not been effective as a put-away pitch. The problem is that, over his career, hitters have only offered at that pitch 36.07% of the time, which is pretty low. In order for the pitch to be effective, it needs to generate swings and misses. While Hughes’ fastball has a whiff rate of 9.51%, the curve is at 7.50%. Batters just aren’t fooled by the curve and aren’t chasing it.

This led to Hughes relying even more heavily on his fastball in 2012. He went to it 65.6% of the time – more frequently than any AL pitcher with at least 100 IP. Even in 2-strike counts, Hughes still threw his fastball almost 3-times as often as his threw his curve.

But something changed in his August 22 start against the White Sox. In that game, Hughes started throwing the slider again, a pitch that he had seen success with in the minors, but has seen limited use in the majors. He only threw 9 of them in that game, but it was the start of something new.

In September, Hughes would throw the slider 28% of the time and saw his fastball usage dip down to 58%. In 2-strike counts, he went to the slider 44% of the time and the fastball 47%. He was using it as a put-away pitch. The results were a 23.2 K% and his best monthly FIP of the season (3.82).

Hughes ended up throwing his slider 165 times this season. It generated swings 55.15% of the time and a whiff rate of 20% – that translates to a solid 36.26% whiff/swing rate.

Obviously, this data needs a small sample size disclaimer. It could just be random noise, but it is encouraging. If Hughes can use the slider as an effective pitch, especially in 2-strike counts, it could allow his fastball to be more effective because hitters would actually have to worry about one of his breaking pitches. If some of those foul balls start turning into swings and misses, Hughes could be looking at a great season.

PITCHf/x data courtesy of brooksbaseball.net and baseballprospectus.com