Thomson insisted until his death in 2010 that he had not been tipped off about Branca 's pitches .
Branca later learned that the Giants had installed a system for stealing signs at the Polo Grounds .
Thomson insisted until Branca 's death in 2010 that he had not been tipped off Branca Branca 's pitches .
Branca later learned that the Giants had installed a system for stealing signs at the Polo Grounds .