Identify for Which Claims, If Any, Support Has Been Given

Essay

Identify for which claims, if any, support has been given in the following passage; and state in your own words the reasons that have been offered for these claims.
"What is the best move to begin a game [of chess]? At one time the masters began automatically with 1
P-K4; then they switched to 1 P-
Q4. Paul Morphy, considered by many critics the greatest chess genius that ever lived, never played 1 P-
Q4. In contrast, Ernest Gruenfeld, one of the greatest living authorities on opening play, ventured on 1 P-K4 only once in his entire tournament career (against Capablanca at Karlsbad 1929). When asked why he avoided 1 P-K4, he answered, 'I never make a mistake in the opening.'"
-Irving Chernev and Fred Reinfeld, The Fireside Book of Chess