The lanky former high school swimmer has gone through multiple swing changes when, in 2008, he ran into some "dark days" with his golf game and almost "lost" it.
"I put a lot of work into it and the last year it's finally come around where I can attack and put four good rounds together," Erwin said. He finished tied for 17th at last year's Amateur, his first.
His biggest mistake on Wednesday was thinking too much about another player - leader Sam O'Dell, who holds a commanding nine-stroke advantage into today's final 18 holes.
"I didn't have my swing at all, I never could get anything going," said Erwin, who shot a 3-under 69 on Tuesday at the Greenbrier Course, but followed with an 81 Wednesday. "I came in here today thinking I had to go shoot a 64 to catch Sam, and that's the absolute worst thing I could've done. It put me under undue pressure."
Erwin is quite aware that it's going to take more than four rounds at the Amateur or an exemption for a top 15 finish to get money to turn professional. The average age for the PGA Tour rookie in 2013 is 31, so he already faces an uphill battle.
The sales account manager for Dr. Pepper/Snapple struggles to find time for practice with 50-60 hour work weeks, and a wet summer in Putnam County put a damper on regular rounds at Sleepy Hollow.
Considering where Erwin has been, however, he can be patient, and is comfortable with that conclusion, as long as it results in another.
"You can't find sponsors until you win something," he said. "Like Sam (O'Dell), he could play as a tour pro if he dedicated himself to it. There's so many good players, until you prove you can be clear cut dominant at this level, nobody's going to throw money at you.
"The only plan I have is to continue playing well in these things to the point I can finance it myself or get to the point where I break through."
Contact Assistant Sports Editor Rich Stevens at richstev...@dailymail.com or 304-348-4837.