Letang is a head case. Most pens fans struggle to admit that. While the rest of the "core" has grown up now that they are all staring down the barrel at 30. #58 is still throwing hissy fits. I wouldn't call Letang the engine though. A crucial piece for sure, but even when he goes off on his tangents, the rest of the team doesn't follow.
Not talking about getting him off his game really. Just mean you have to beat him down physically so he can't be as active with the puck.
In the Flyer series you could see them looking over their shoulders as the series wore on. Checking up, getting rid of pucks faster than they should have because they were tired of getting slammed into. Especially noticed this with Ghost.
Caps need to do the same thing to Letang and if he takes a penalty along the way all the better.
Caps are underdogs in this series, very few will pick them, they have to have a perfect game plan to win and shutting down Letang has to be a huge part of it.
Honestly I think Holtby playing like god and MAF coming back are the best chances the Caps have.