A proverb meaning that great horses (or great people) often have quirks — excellence often comes with eccentricities or faults.
彼は仕事ができるが扱いにくい面もある。まさに名馬に癖ありだ。
He is capable at work but has difficult sides. Truly, a great horse has quirks.
名馬に癖ありと言って、チームは彼の欠点を受け入れることにした。
Saying 'a great horse has quirks,' the team decided to accept his flaws.