About twenty years ago, "good swing" means this kind of swing, especially for left handed hitters. And Eddie Murray's swing has same impression as Tony Gwynn's it. In fact, their swing was completed extremely as swinger type. However, In today's MLB, this kind of swing can almost not be seen. Left handed hitter's swing was changed while last twenty years. Following hitters show the new fashioned swing of left hand hitter.
Jason Heyward
Justin Morneau
Sam Fuld
On the other hand, following hitters show vestige of classical left handed hitter's swing.
Jarrod Dyson
Chipper Jones
Justin Smoak
Joe Mauer