hey all, it appears the ATP will now adopt three challenges plus one additional in the tie-break starting with the australian open. ive always been an advocate of this number of challenges and am glad that its finally being implemented. again, the benefits of this number are: 1. hawkeye works. bottomline, lets have more calls corrected. 2. players were hesitant to use challenges with only two. often they'd horde them until the end. now with an additional one, they'll use hawkeye more. if you're having a hard time understanding the psychological impact one additional challenge makes, just imagine baseball with two strikes instead of three. discuss.