Complex sentence: Two Southern California (USC) players have won the trophy in the early years of the 21st century and two won it subsequent to Palmer, but no non-USC player from the West Coast has won since Stanford's Jim Plunkett in 1970.
Split into simpler sentences: Two Southern California (USC) players have won the trophy in the early years of the 21st century and two won it subsequent to Palmer. No non-USC player from the West Coast has won since Stanford's Jim Plunkett in 1970.