He started out at mid-1400’s and after two years of hard work got to 1770. Good job! His goal became to go over 2000. He thought he could do it when he beat a couple 1800's at the local club in some offhand games. The problem is he can no longer play against average and below average players in tournaments; he’s meeting 1800-1900’s with an occasional 2000 thrown in. The result? His rating is plummeting and he’s back to barely over 1600. Going 0-4 in his last tournament didn't help. He is very discouraged and his solution to the problem is…you guessed it; change his opening repertoire and study more tactics. Why isn’t he playing solid mainline openings, refining his positional judgment and becoming proficient at endings? He’s waiting until he is at least 1800 to do that.
This tells me that he already thinks he won’t get to over 2000 without those skills and logic tells you he must hone those skills to successfully overcome the 1800-1999 crowd. Yes, they still make tactical errors but they aren’t as blatant and they make them less often than lower rated players. It takes more than studying tactics until he pukes but he can’t see it.
My prediction…he won’t make it to over 2000 any time soon. I quit offering him advice a couple years ago because he told me he knew what he was doing. Some GM who was probably rated 1600 for a month and can't relate to average players told him to play gambits and study tactics. Did I mention the guy has written a couple of books on those subjects? Do you think he has a vested interest in peddling anything? These hucksters keep offering shortcuts and promises of quick success. They don't work in life and they don't work in chess.