Dredge

Dredge has got two problems. The first one is decks that are quicker then it and the second is hate-cards.

Quicker decks:
This is for me the biggest problem for dredge. These decks are combo decks that usually wins with Oath of Driuds (Storm/Time Walk-chaining combo) or regular storm decks. It is very important to recognize what kind of deck you are up against to know what your gameplan is.
Dredge has very few answears to these type of decks. All decks run Cabal Therapy and apart from that you have two viable options:
Unmask & Flame-Kin Zealot. Unmask makes you run more black cards in your 75 (full playsets Golgari Thug, Ichorid, Darkblast and so on) and FKZ makes you run at least two Dread Return to get one in the graveyard "in time". (Running more then one copy of FKZ is not usual but can be viable)
Playing Leyline of Sanctity could work but it is a lot of all in and thus not worth it imo.

Hate cards:
At the moment the three most common stategies against dregde is also the best answears so far.

• Rest in Peace/Leyline of the Void - By far the hardest to work around. Any card you discard with Bazaar will get removed, drasticly limiting your "digging for answear" ability. Wispmare and Nature's Claim are good here but the decks that play RiP/LotV usually pack a lot of counters. If they run a quick combo this will be a hard MU.

• Ravenous Trap - If you suspect your opponent of playing this you will need to keep Unmask in and/or cast a Cabal Therapy for it before you go off.

• Grafdiggers Cage + Mental Misstep - Very easy to play around this combination. Ingot Chewer is a great answear that can only be countered by Mana Drain and Force of Will. Any discard spell will secure the destroy effect and win from here. You can dredge up and cast (FOR MANA!!!) Golgari Thug and Stinkweed Imp and then win either by tokens from Bridge from Below or just straight up combat damage from your tiny critters.

I like the quicker deck better. Chaining Sun Titan by recurring Blood Ghast, with a couple of Fatestitcher. You find a Cabal Therapy really quick, or just win from putting your library in your graveyard. Being quick rivals other quick combo decks.
You can find the deck here: LINK
I like the explosiveness and the resilience of the deck. Unless your opponent wins t2 you will.. and unless your opponent has +3 hate cards g2-3 you win. The only thing I dont like about the deck is that its missing Unmask but theres just no place for it in the deck.