East 1:
1: Keeping yakuhai over 2 or 8 usually slows your hand down. Since you're dealer you should be going for fast hands. Discard one of the sangen tiles next time.
3: the 9 is more tile efficient than the yakuhais since it frees up the 4m and also goves you another pair in case the 6688s turns into an iipeiko.
6: read up on 亜リャンメン. I don't know what it's called in English. I'll stop telling you to pointing out tiles that are much stronger than the white you have kept for much longer than necessary.
9: assuming we're still keeping the white, you should've discarded the 4m as the 6m and 7m would've formed a ryanmen, allowing you to draw 8m and riichi. This is useful to keep in mind for all middle waits.
12: please read up on tile efficiency. As a general rule ryanmen > pairs. With a 56s you could accept 4 and 7s while with 66s you could only draw the last 2 6s. I understand that this might've been a defensive play, in which case good job.
I see you managed to avoid death and get tenpai, to reach this end your discards were reasonable with one notable exception being the last 6m. You could've discarded 9m. Not only is 9 generally much safer it is also a genbutsu. It seems you were to fixated on 789m being a sequence you failed to consider 6789 as a shape. I'll stop pointing out tile efficiency mistakes in the following rounds but please do work on that.
East 1 r1:
Nice
East 1 r2:
11: if you drew a 5m and ended up with 69m tenpai you would've been in furiten.
12: You upped your shanten with that. It was a pretty difficult hand but the correct answer definitely wasn't 4s.
Mangan tsumo on your dealer round rip
East 2:
Please stop holding on to yakuhai, even for the sake of safe tiles it's too early for that. Not having a yaku is scary but with good tile efficiency riichi is really not that hard
4: As a general rule the discard order for yakuhai is round wind (other's) > dragons > self wind because of their difference in usefulness for others. East is particularly scary because it can give the dealer 2 han.
Good job not dealing in.
East 2 r1:
11: wtf nigga check all the tiles before tenpai. If you discarded 3s you had a ryanmen.
Omigotonanoja I guess that's a pretty bad mistake.
East 3:
1: Since all the tiles that could improve 9p could be used to improve the 6p, if you have both in your starting hand it's better to discard the 9p. This is a concept called effective tiles overlap.
7: The 5m can pair with one of your two 7m for a middle wait.
East 4:
11: You were in iishanten for chiitoi, stick with it. At least discard the 7m if you wanted to keep your hand flexible. The 1s also would've caused you to be in furiten.
South 1:
Please sir the yakuhais just drop them
6: The 7s could have been your pair, cut the 2 1m and get a ryanmen.
8: If you cut the 45p you could've kept the 8s dora. It's pretty cheeky.
9: if you discarded the 5s you would've been tenpai. At some point the dora isn't worth it anymore.
South 2:
3: You're locked in to tanyao. Discard the yakuhais. You made your hand a lot worse by discarding 6m.
South 3:
2m is better than the bird but otherwise good job
South 3 1r:
For 689 discard the 9. The 6 can turn into a ryanmen.
South 4:
Get fucked lmao learn defense.
I would've folded the moment riichi came down. Since you were already in first the goal would've been to end the game. If you can't end the game at least not drop to third. Your hand still looked pretty shit so pushing was going to get you ronned more than likely. Even if you had a great tenpai I still would've folded since you had nothing to gain but everything to lose.