This is by far the hardest challenge in Tekken 7 Ultimate Bowling DLC.
The key is to aim for strike at all the regular & Heihachi frames and at least hit first two splits, so that you can miss the harder splits in later frames and have room for few bad luck shots. (like the ones I got at 44th & 47th frames)
Extra balls you get from the Heihachi pin strikes and first two splits are really important if you want to have a good shot at getting to strike 50.
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