Having spent most of his career working on multiple series at the same time, his two longest works (Abu-san and Dokaben) surpassed the almost unheard of lengths of one hundred and two hundred collected tankobon respectively.
Though he debuted in the late 50's, his proper breakthrough and shift into the baseball manga he is now known for really began in the early 70's when he began serializing in Weekly Shonen Champion, the magazine where he has done his most work, virtually always having an ongoing series with them since 1970 apart from a few short breaks in between series (most of these breaks being two months or less).
He also has explored both the seinen and shonen markets simultaneously with his longest work (Dokaben) being a shonen and his next longest-work (Abu-san) being a seinen. On top of having long-running serials in some of the biggest manga magazines of all time like Weekly Shonen Champion, Weekly Shonen Magazine, Weekly Shonen Sunday and Big Comic Original (often simultaneously) he has also been one of the highest profile creators in a number of failed magazines where he published series for most of their run.
Also, with weekly serials still ongoing in his late 70's, he is by a significant margin one of the oldest active mangaka in the weekly market of the industry.