In this episode Jerry and George return to their old high school hang out and find that George's top score on the Frogger arcade game there still stands. Seeing this as something to validate his existence (possibly the only thing he's ever been good at?) George purchases the machine. Slippery Pete (a friend of Kramer's) is enlisted to jury-rig a battery to the cabinet so that when he moves it George won't reset the high scores.
Unfortunately Mr. Pete gets a little carried away and George finds him playing the arcade game while running off of the battery. With three minutes of power remaining and the only available power source across a busy street George is forced to play Frogger with his Frogger. As is typical for George, disaster ensues.
According to a post I found on usenet, the high score screen on the arcade machine in this episode read like so:
1. GLC 860630
2. GCB 303800
3. ECC 303780
4. GKC 202050
5. CMN 101970
6. KMC 303800
7. MMC 303780
8. PTC 202050
9. MTF 101970
10. JFS 101970
Supposedly the initials will be familiar to Seinfeld fans however that's not what I noticed immediately while watching the show. Despite being the hinge on which this entire subplot rested, in real life Frogger does not record initials! * The top high score is treated to a 1ST label, the next gets 2ND and so on.
* - Unless additional chips are added to the machine. This can be accomplished by following the instructions at http://www.jrok.com/sohs/frogger/frogger.html Of course it's highly doubtful that this information was widely available in the 80's (when George's high score was supposedly created).