When Semyon Dukach was a student at MIT, he ran the best-performing Blackjack team the school has ever had. On a typical weekend, Dukach and his team of 60 students could win up to $150,000 by using a legal, card-counting system they created at MIT. They were so good, the group amassed more than $4 million and were often threatened or banned by casino managers.

Read more: Former MIT Blackjack Shark Whose Team Won Millions From Casinos Is Now Investing In Tons Of Startups

Starting in February, Semyon is taking on a position as a Lead Mentor, at Techstars, the Number 1, mentorship driven start-up accelerator in the world. Techstars provides startups with seed funding from over 75 venture capital firms and angel investors, as well as in-depth mentorship from the brightest entrepreneurs from around the globe. Because of the level of commitment involved in mentoring at Techstars, Semyon will not be investing in any new startups for the next three months.