2008-09: Blackwell earned his second varsity letter for hockey at Massachusett's St. John's Prep and played for the Junior Valley Warriors U16 team that reached the 2009 USA Hockey Nationals.
2009-10: Blackwell was a team captain for St. John's Prep as a junior and was named a Catholic Conference all-star. Blackwell also played for St. John's state champion lacrosse team.
2010-11: Blackwell committed to playing for Harvard in 2012-13 while playing for the Junior Bruins in the Eastern Junior Hockey league prior to the high school season. He set a school scoring record at St. John's Prep as a senior, finishing with 33 goals and 33 assists in 25 games. He had 11 points as St. John's reached the finals of the Super 8 State Championship and was named the Robbie Ftorek Player of the Year by the Massachusetts high school coaches. Ranked 173rd amongst North American skaters in Central Scouting's final rankings, Blackwell was selected by San Jose in the seventh round (194th overall) of the 2011 NHL Draft.
2011-12: Blackwell had a good start to his NCAA career as a freshman at Harvard University where the quick skating centerman scored five goals along with 10 assists and a minus five rating while taking 46 PIMs (2nd on team) in 32 games. The freshman was involved in or set-up many important late-game goals for the Crimson this season.
Blackwell plays with energy, drives fearlessly to the net, has a solid hockey IQ and can be a shooter but also has good offensive vision to be a playmaker. The stocky forward will need to add more muscle to his small build while improving his overall defensive game and learning to uses his quick accurate shot more often. He's a real longshot to make the NHL at this time but his work ethic, desire and passion are extreme high along with three more years at the NCAA level.
Blackwell will be playing his sophomore year at Harvard for the Crimson and will be expected to take on a bigger role in the team's offense this season. He needs to keep improving his overall game over the next three years of his development in the NCAA.