Sinnoh Stone

1) Fight one of the three Gym Leaders once a day. It is found on the “pokemon nearby” slide.
2) Fight a friend (win or lose, doesn’t matter) three times a day in any league.
3) Chances are rare you will get a stone on your seven day streak or field research streak

I do not believe you that you had 97 eligible battles and received 0.

First of all, in a week you have a maximum of 28.

97 battles and 0 Sinnoh stones!? That's madness!

I'm not going to question the 97 battles, I will say this though with my daily battle partner being a free to play account, it is possible to have been "awarded" a sinnoh stone but having a full inventory the game warns you, you don't get it after the fact, so maybe full inventory? Good news for anyone that experiences this, the account can still get rewards that day after clearing bag space, it just won't be the same rewards that it tried to give the account earlier.

I posted this yesterday: https://pokemongo.gamepress.gg/q-a/all-i-want-christmas-sinnoh-stone

Today, my victory over Blanche was finally rewarded with a Sinnoh Stone!

Your turn will come sooner or later. Hopefully sooner.

I think, they boosted Stone rate, or just incredibely luck? Today all 3 battles with my sister gave me Stones, battle with Candela( easiest trainer- 1 Swampert without using shield can beat all with only half hp lost) and reaserch also. 5 stones in 1 day, while before that, i just earned one from battles, and 0 from trainers and Research. But my sis also had 3 from battles and 1 from research, just not from Trainer.

Its hard to call this pure random : O

I have never received a Sinnoh Stone from PvP or trainer battles. The one and only stone I’ve received was from seventh day research work back in mid-November.
This is incredibly maddening and making me want to delete the game.