Williams went 2-16 from the field and 1-9 from three in the series.
By any metric, Deron Williams had a terrible finals series. He couldn't make a shot (2-16 from the field, 1-9 from three for the series), couldn't guard anyone (122 Defensive Rating) and was a general liability every time he was on the court. When all was said and done, he averaged 1.0 points and 1.2 assists in 12 minutes per game for the series.
Stats aside, you know you're not helping your team when the opposing side is actively excited for you to get into the game. Williams' former Cavs teammate Richard Jefferson spoke about Williams' brief tenure in Cleveland on his 'Road Trippin' podcast. Long story short, Williams' stay in Cleveland was not a particularly positive experience...for player or team.
Richard Jefferson: “When you ask Deron about golf, his eyes light up. When you ask Deron about MMA, his eyes light up.”
ESPN's Dave McMenamin: “What about when you talk to him about coming off the bench for the Cavaliers?”
Jefferson: “His eyes did not light up, his eyes did not light up.”
Chris Geeter: “What about when the Warriors saw him coming off the bench?”
Jefferson: “Their eyes lit up.”
Jefferson laughed before he gave that final answer, and it didn't sound mean-spirited it all. Yet all humor is rooted in truth, and the truth here is Williams had no business being on the court in that series. Jefferson and his Cavs teammates know that now, and it appears they knew it then.