Never said he did not throw fewer 4-seamers. He still threw almost 10% of his pitches that way though, so a little more than a "show me" pitch. The larger point is the curve. It used to be terrible. Now it is decent. Though he still only threw it 12.9% of the time.
He was not a good pitcher when he just threw sinkers all the time. Even before the ill-advised 2-seamer experiment. It was not until he started mixing in multiple good pitches that he started to get better. I know you have loved Eflin over the years. It has just been for the wrong reasons. You kept making excuses for his bad pitching because of his knees which were really a minor factor.
He is never going to be a number 1 or 2 starter. His pitches are not good enough. He can be a mid-rotation guy with a decent 4 or 5 pitch mix. Be happy with that.
Fangraphs breakout article with Eflin:
Like Musgrove, he relied on his curveball a lot more in 2020 than in the past, and he finished as one of the top ten curveball pitchers in terms of results (ninth in wRC among all pitchers). The biggest difference was the willingness to use the curve as a two-strike weapon. In 2019, Eflin only threw the curve on two-strike counts 3% of the time. In 2020, that went up to 19% against lefties and 24% of the time against righties. The result? Twenty punchouts via the curve compared to 28 in 2019 in about triple the number of batters faced.
