LONDON, Nov 22 (Reuters) - The biggest of World Cup shocks paid out for at least one prescient punter who correctly predicted Saudi Arabia would stun Lionel Messi's Argentina 2-1 in their opening match in Qatar on Tuesday.

A football fan lost more than $160,000 (134,000) after placing a seemingly safe bet on Argentina beating Saudi Arabia. Online betting platform TAB has confirmed that someone placed $160,000 on Lionel Messi's side to kick off their World Cup campaign with a win in Doha.

Slot machines operate on the c. variable ratio schedule of reinforcement. This means that there is a random and unpredictable amount of time between each reward (a win on a slot machine), as long as the person keeps playing the slot machine.

Interesting question- slot machines are actually based on a degree of randomness in each individual play, but the payouts when those random events produce a winning combination are controlled to ensure that only a certain percentage of money played is paid back. Typically in the high 90% range.