What the heck happened with Ryan O'Hearn?

Not an O's fan. I knew O'Hearn had a much better year last year, kind of out of nowhere, but I just now saw how he completely transformed himself this year. Cut his K rate in half while more than doubling his walk rate! That's almost unheard of.

I was surprised when I couldn't really find any articles discussing what happened.

Has he said what adjustments he made? Have you as fans noticed anything in particular?