2019 ITTF Challenge Series  The 2019 ITTF Challenge Series is the third season of the International Table Tennis Federation's secondary professional table tennis tour, a level below the ITTF World Tour. From this season, the ITTF Challenge Series will be split into two tiers: Challenge Plus and Challenge. The tournaments in the 2019 tour have been split into two tiers: Challenge Plus and Challenge. Below is the 2019 schedule announced by the International Table Tennis Federation: