トムさんはマージャンをやるのは久しぶりだ。

English Translation

Tom hasn’t played mahjong in ages.

Completely opposite meaning…

トムさんは長いことマージャンをやっていない。= Tom hasn’t played mahjong in ages. = The last time Tom played mahjong is like 5 years ago. Since then, he has NEVER played it.

トムさんはマージャンをやるのは久しぶりだ。= It’s been a while since the last time he played mahjong, and he is about to resume it.