I had this idea - out of the batkids, who'd have the most scars?
Bruce is obviously the all-round winner, followed by Jason. I know the Lazarus pit gets rid of scars and so any injuries he got before then, he's lost, but Jason strikes me as such a reckless guy who never gets proper medical care when he gets stabbed or shot in all the alleys he's stalked in Gotham that he'd quickly rack up scars and get second place. (Also I think he'd have autopsy scars, but that's a post for another day)
Next contender would be Damian. I think, given his year of blood, despite having Ra's care, he would still rack up quite a lot of scars, more than Dick.
Then Dick: not because he doesn't have experience, but because at some point after Jason's death, he'd become a lot more cautious about taking care of himself, for Bruce's sake. If Bruce lost another kid, or another child got crippled, he wouldn't be able to handle it.
And finally, Tim. Because he's a wee bit insecure and believes that compared to the other kids, his strength is with his mind, rather han his body, and his fight style would reflect that. Stealthy, quick, not at all brawl-like.