Made it to mythic# !!  64% win rate from plat 4 to mythic.

https://www.reddit.com/r/MagicArena/comments/14wf7no/made_it_to_mythic_with_my_second_combo_deck_64/

Deckbuilding:

the Scurry Oak / Rosie combo + the Sam / Cat combo, CoCo can pull any of the 4 combo pieces.

Okay the biggest question you might have is, why stuff two different combos into one deck?

The short answer is CoCo, the long answer is this allows me to put 16 combo pieces (threats) in there. You have a better chance of putting together at least one combo, and every one of these 16 pieces are must-remove threats for your opponent. You can try to exhaust their removals! More than once I've put together one combo only to get removed, and then win with the other combo.

And these two combos do have actual synergies besides just CoCo. Altar of Dementia can turn the ScurryRosie combo into a win on the same turn. Food generated by Rosie can be used by Cat or Sam's second ability. Sam and Rosie are both legendary halfings, to the delight of Delighted Halfing and Secluded Courtyard.

Piloting:

Mulligan is half the battle.

For my starting hand I'd like to see a clear path towards completing one side of the combo, or towards a CoCo. If I don't see one, I mulligan. If you lack mana (lands or mana dorks) you have to assume you'll draw them.
At a 6-card hand, consider keeping if you have a mana dork + Eldritch Evolution, assuming you'll draw into one of the 16 combo pieces later.
At a 5-card hand you have to be even less picky, if all else looks fine but you lack a sac outlet, you have to bite the bullet and assume you'll draw one later. (There's 8 of them in the deck.)

The worst enemy is discard decks: Thoughtseize, Break Expectations, ... it's really an emotional roller-coaster to get a good opening hand and then BAM T1 Thoughtseize.

Contrary to popular belief, cards like Soul Warden do not save the opponent from SamCat. Because it's a triggered ability that goes onto the stack, as long as you perform the SamCat combo on the opponent's turn, the APNAP rule will make your abilities resolve first and theirs stay on the stack. So just keep doing your combo, and don't resolve their abilities on the stack.

The One Ring does not save them from SamCat either 😉 but Grafdigger's Cage does, at that point you have to win with ScurryRosie instead. Solemnity kills ScurryRosie, at that point you have to go with SamCat.

• Mana dorks speed you up, and can be sacrificed to Ashnod's Altar for further speed-up or sacrificed to Eldritch Evolution.
  Save Eldritch Evolution for last; typically you want to play CoCo on their end step, and if you don't hit a combo, play Eldritch on your turn to find the missing piece.
• CoCo being an instant is probably the best thing for this deck. I don't want my CoCo products to get boardwiped, so I play CoCo during opponent's turn, especially when they just played a board wipe on my mana dorks -- at that point hold full control, tap for mana, resolve the wipe, then immediately cast CoCo.
• If you have Altar of Dementia on the board and you're desperately looking for Cat, consider sacrificing mana dorks to mill yourself, see if you can mill a Cat. btw generally speaking, when I pop off my SamCat combo with this altar, I always mill myself. Don't wanna give opponent any accidental graveyard resources...
• The more food you have, the more resilient your SamCat combo is. Say you activate the SamCat combo and opponent plays an instant removal at Sam. If you still have one more food, you can activate Cat's ability again to bring it back again. Just keep doing your combo and don't resolve their abilities on the stack.
• Sometimes you have to take a gamble and hard cast Rosie on your turn. Usually it's the last ditch effort; but if you know the meta, some decks like elves don't bring board wipes, so it would be actually safe to play Rosie on your turn.

And finally, yes, it's a lot of clicking. Get a comfortable mouse and mouse pad 😉 be patient, click efficiently and don't panic, I've only been screwed by the timer like once ever. (and I still won that one.)

some notable matches:

first ScurryRosie then SamCat https://www.17lands.com/user/game_replay/20230708/1b825dd4e0034a95ba464cad08316d54/0

they never know which side I'm gonna combo with https://www.17lands.com/user/game_replay/20230710/75f8055466504c478f9a3d90bd068727/0

Statistics:

64% winrate overall, with 70% on the play and 59% on the draw
59% of the wins were won by SamCat, and 41% won by ScurryRosie.

Roughly half the wins were with the help of CoCo, and the other half won without needing CoCo. On the other hand, among games where I played CoCo and it resolved, I won 71% of them. meaning my CoCo's whiffed 29% of the time... ¯\_(ツ)_/¯

Lastly, if more people become aware of this deck (and the weaknesses of this deck), I'm sure the win rate will fall. But I doubt this post will have that kind of reach lol

Mythic Proof: https://i.imgur.com/TWADSfN.png