close one... as roddick's career is not over yet, he will probably win this one at the end !
let's have a look at some significant stats.
GS
slam W : 1-1
slam F : 4-4
slam SF : 9-8 roddick
slam QF : 16-13 roddick
but... chang made the QF at all slams whereas (so far) roddick's best perf. at RG is a 3th round in his first appearance in 2001 (retired vs hewitt). also, chang has reached the final of 3 of the 4 slams (2 of 4 for roddick).
masters
chang : only went out of the RR stage once in 7 attempts, but made it to the final in 1995.
roddick : 3 semi-finals (2003, 2004, 2007)
titles
chang 34-27
(finals : 58-42)
but roddick has won titles on all surfaces, where as chang never won on grass.
davis cup (if needed)
roddick : 31-11
chang : 8-4
(both only played single matches)
rankings
best : roddick #1, chang #2.
top'5 weeks : 199-172 roddick
top'10 weeks : 369-326 chang