Woll played 4 games for the Leafs this season while Petr Mrazek was sidelined with a groin injury. During his brief stint with the Leafs, Woll posted a 3-1-0 record and a .911 sv% with one shutout.
In the AHL this season, he's posted a 5-2-0 record with an identical .911 sv%. The American netminder has missed some time of late with a knee injury, but clearly the Leafs have faith in the 2016 third round pick's development and his recovery.
Woll's new deal will pay $766,666 per season for 3 years. The first year is a 2 way deal, meaning that Woll will make a different salary depending on whether he is in the NHL or AHL. The last 2 seasons will be one way, which means he will earn his NHL salary no matter where he plays.
The contract switching to a one way deal may indicate that the Leafs are planning to make Woll a full time NHL backup in the near future. Likely meaning that at some point, Jack Campbell or Petr Mrazek could be moved out. It could also be the Leafs making sure that they have an option in the back-up slot should Campbell walk away in free agency. Either way, having a goalie capable of playing NHL games at such a low cap hit is an excellent thing for the Leafs.