Game Theory Intro

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Game Theory Intro
Game Theory Course:
Jackson, Leyton-Brown & Shoham

Game Theory Course: Jackson, Leyton-Brown & Shoham

Game Theory Intro

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TCP Backoff Game

Game Theory Course: Jackson, Leyton-Brown & Shoham

Game Theory Intro

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TCP Backoff Game

Should you send your packets using correctly-implemented TCP
(which has a “backoff” mechanism) or using a defective implementation (which doesn’t)?

Game Theory Course: Jackson, Leyton-Brown & Shoham

Game Theory Intro

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TCP Backoff Game

Should you send your packets using correctly-implemented TCP
(which has a “backoff” mechanism) or using a defective implementation (which doesn’t)?
• This problem is an example of what we call a two-player game:
• both use a correct implementation: both get 1 ms delay
• one correct, one defective: 4 ms for correct, 0 ms for defective
• both defective: both get a 3 ms delay.
Game Theory Course: Jackson, Leyton-Brown & Shoham

Game Theory Intro

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TCP Backoff Game
• This problem is an example of what we call a two-player game:
• both use a correct implementation: both get 1 ms delay
• one correct, one defective: 4 ms for correct, 0 ms for defective
• both defective: both get a 3 ms delay.
• Play this game: in your head; with a friend; on our online system.
• Some questions to discuss after playing:
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What action should a player of the game take?
Would all users behave the same in this scenario?
What global behavior patterns should a system designer expect?
For what changes to the numbers would behavior be the same?
What effect would communication have?
Repetitions? (finite? infinite?)
Does it matter if I believe that my opponent is rational?

Game Theory Course: Jackson, Leyton-Brown & Shoham

Game Theory Intro