Ben Brown's knuckle curve has been the key to his recent success with the Cubs

After getting rudely welcomed to the big leagues by the reigning World Series champion Texas Rangers, Chicago Cubs pitching prospect Ben Brown has settled in nicely, eating key innings for manager Craig Counsell as the team awaits the returns of both Justin Steele and Jameson Taillon.

In his first MLB start Brown, who isn't yet fully stretched out in terms of pitch count, gave Counsell 4 2/3 scoreless frames of three-hit ball, striking out five and walking only one in the Cubs' 5-1 win over San Diego. He, like Steele, primarily relies on two pitches - a mid-to-high 90s four-seamer and a knuckle-curve. The righty has a change-up, but scarcely turns to it, throwing it just 1.2 percent of the time this season.

Ben Brown has showcased two plus pitches in his limited MLB work

As much hype as that fastball comes with, especially given the lack of velocity Chicago's battled through in recent years, that hasn't been his putaway pitch. He's gotten far better results on the knuckle curve - and it's not hard to see why.

Brown has turned to that pitch just over one-third of the time, primarily relying on that overpowering fastball against hitters. And when he's gone off-speed, the results speak for themselves: a 46.9 percent whiff rate and an XBA of just .211, a major improvement over the 14.6 percent whiff rate and .399 XBA against his four-seamer.

Despite that, Counsell has praised Brown's fastball - and it no doubt plays a big role in why his offspeed stuff has worked so well. He's hit 98 MPH on the gun with his heater, giving a roughly 10 MPH difference between the two pitches (that also, obviously, move in very different ways).

As he learns the ropes of big league pitching on the fly, his knuckle curve has graded out very strongly, but I suspect as he settles in more and more, pitching coach Tommy Hottovy will look to help him develop that change-up a bit more so he has more looks to keep opponents off-balance as the season wears on.