Someone who watches you die, lets you lie there, and doesn't even bother to offer you a raise. When you get upset about it, they then try to justify why they had every right to be a complete douche to you, all the while dropping F-bombs, calling you uncultured, and basically showing you how much of a hypocrite they are with thier juvenile behavior. All this after you tell them it's considered common courtesy to offer a raise to someone regardless of whether or not they ask.

In summary, a bad player is someone who needs to have an excuse to help someone else.