You have a story, a script the size of a matchbox, but fairly right for the purpose it serves. Characters' backstories easily fill that purpose too, being side stories on their own, keeping us entertained. It only stretches a bit much around the end, otherwise, there's nothing to get bored of: plenty of fights!
On the artistic side, Grappler Baki is a failure. Everything from the chara design to the animation is cheap to the point even Baki doesn't look the same from one one scene to another. Thankfully, he has red hair, but you should see him trying to smile: it's sometimes dreadful! The only thing worth saving is the tension, the grim side of the show. The savagery accommodates well with the poor design and animation and the good but unremarkable music.
Oddly enough, the flaws are nothing much compared to the enjoyment procured. You can forgive easily when you seek fights and the show offers you fights. There is a scent of Bloodsport, backstories with the assumed flavor of 80s' american action movies, mixed with chinese kung fu flicks. It doesn't promise much, but it delivers.
(Like an undertalented Morricone-like, but taken as a compliment.)
