Getting S on Shaco

I have recently started playing Shaco in the jungle because all the lanes aren't very fun at all anymore with assassin laners and cc tanks. Anyway, I have good games and bad games as Shaco, which is expected on anyone but the games that I do very well in I can't get an S. I have him level 6 and I have been spamming games with him and I can't get an S, only S-. In the last day or so I have gotten three S- on games that I did very well in. There has been a couple times where I have a ton of gold and they surrender out of nowhere and I can't spend it and it really feels like I would get an S if I could have just spent the gold. I don't know what to do. I just don't get how it's actually possible when I have a lot of kills, not very many deaths, good assists, and a ton of farm for a jungle and even completely controlling objectives. There was a game where I killed the enemy in his jungle, had good farm, and got every single dragon, rift heard, baron, and elder dragon, almost all solo and no S. I thought maybe I would get one over time but nope.