Jordan Speith - The Masters Win Probability
Jordan Speith - The Masters Win Probability

Jordan Spieth strides up to the tee tipping his cap to acknowledge the growing roar as the crowd buzzes in anticipation. It’s the 12th hole during the final round at Augusta National and Spieth is 5 under par with a 3 stroke lead seemingly destined to become only the fourth player to win back to back Masters Tournaments.

Spieth steps into the box over looking the hole and Rae’s Creek as the gallery hushes convinced they are watching Masters history. After striking the tee shot he immediately lowers his head, knowing what we will all find out after the ball settles and hole ends; Spieth is in the water and we are all watching the wrong kind of history.

Looking at the trend of Spieth’s round we have to remember a couple key points to fully understand how improbable his ultimate collapse really was:

Spieth was the defending Masters Champion
He had birdied holes 6, 7, 8, and 9 to be (-7) for the round and (32) through 9
He had a 5 stroke lead through 9
Only 2 other golfers were under par for the tournament through 11 holes
The 12th hole was a par 3

To give some analytical perspective, BallStreet Trading, a live event trading app, was running a live market for the 2016 Master Tournament which let players day trade win probability of each golfer. As Spieth ended the 9th hole he was trading at over 93% to win the tournament. The market had fully priced in a Spieth championship. Even after he bogeyed holes 10 and 11 the traders on BallStreet kept bidding north of 90% with his 3 stroke lead as he teed off on the 12th hole.

By the time he went in the water for the first time sellers already started moving in and hitting bids driving the market down into the mid 80’s. After the drop and second ball into Rae’s Creek all hell was breaking loose as his shares were crashing through 60% and finally finding some support at 45%. This all happened live inside around 10 mins as the markets on BallStreet are all in real time. He went from an almost 20:1 to win to less than even money after that 12th hole.

Players on BallStreet who were able to identify what was happening and act quickly got out of their Spieth shares and ended up making a killing in the market. Those players who ended up buying Danny Willett in the process made even more and found themselves on the top of the BallStreet leaderboard for the event.

The current buzz word in sports seems to be “win probability”. There has been a lot of talk around it especially after the Patriots come back win during this years Super Bowl from a less than 1% chance to win the game. But for anyone paying attention, the Spieth Master’s collapse has to be right up there with the Falcons.

What’s interesting when comparing the two events is looking back at an actual market with players, BallStreet, bidding and offering shares of an outcome to show how a crowd sourced measure of win probability might be different from one sourced from historical statistics. Crowd vs Computer.

Spieth is already set at a 13-2 favorite for the 2017 Masters in April and for anyone looking to trade this years Masters themselves can check out BallStreet Trading where they let members trade Spieth and the rest of the leaderboard’s win probability for their Masters Tournament market this year. Will be curious to see how early people are willing to buy Spieth if he comes into the weekend rounds playing well and with a lead.