'You didn't leave anything on the playing field'?

[Nessie]

Hi,
Please have a look at this:

'The president also called McCain to say that he was proud of the senator’s efforts and that he was “sorry it didn’t work out.”

“You didn’t leave anything on the playing field,” Bush said'

=> Could you please tell me what Bush means? I can't make it out...

Many thanks,
Nessie.
_________________
:(... something we never have again, I know... I guess I really really know.. :(

Sorry seems to be the hardest word...

[Barb_D]

It simply means he didn't give up until it was all over. He made every effort to achieve his goal.