“Even” has a lot of unrelated meanings. This is an informal oral use similar to its use in a question showing doubt. If Seth even shows up (Seth might not even show up. I’m concerned that Seth might not show up) Does he know how to speak English? (I’m asking) Does he even know how to speak English? (I’m asking but I think he might not, and that possibility upsets me a little) Give him directions when he gets here. If he even speaks English. (I think he might not speak English and that possibility upsets me)

"even" here expresses some doubt that "he will show up". "even" has hte sense of more could happen, but him just getting there is an event that may not happen. . The other runners are fast: they have fast times. That guy might not even finish no matter how long we give him. . Your performance was terrible. Do you even know the rules? The sense is that you should not only know the rules but also be good at playing.