1.) Cheap as in mana cost, not the cost of the cards. In terms of money, the deck is a bargain. That generally means it's not good because good cards cost money.
2.) You don't know what deck your exact opponent is playing. That's why you can't "pre-sideboard" your deck. You have to play one game in the dark, then get to make the changes from your sideboard. Doing otherwise is cheating, and will get you disqualified and potentially banned from the game. You have to prepare the sideboard ahead of time in anticipation of what decks you expect to be at the tournament and then hope your analysis was correct and the cards you've chosen are powerful enough answers to improve the deck.
A big part of being a good tournament player is being able to quickly recognize what type of deck your opponent is playing. For instance, I play a lot of Legacy and follow the format pretty closely. I can generally narrow down the opponent's deck to a couple of options turn 1, even if the only thing they do is play a land and pass the turn. I'm probably 95% to know their archetype by turn 2. Being able to do that means I can spend the rest of the game narrowing down the exact list the oppponent is playing. and can immediately start forming a sideboard plan and figureing out how I should be playing the first game.
Tarmogoyf: You have to understand that decks that play Goyf are built to make it good. It's not uncommon to have a 3/4 Goyf come down on turn 2, and that's just the opponent's graveyard. It'll likely have land
. The card gets out of hand very fast and puts you on a very fast clock very early.
Delver: Yes, you also get to attack. However, the decks that play Delver also play a TON of disruption. They're likely got 6-8 copies of counter spells
, so your early plays will not resolve. They've got anywhere from 4-12 cheap removal spells ( Path to Exile
, Lightning Bolt
, Lightning Helix
), so any creature that does resolve dies very soon after. They will get a lot of damage through, and your Blood Artist
s won't do much work because they will get removed very soon. Basically, the opponent will be dealing you minimum 3 damage a turn, and likely only be taking 1-2. It wins that race.
Card draw: Probably a very bad idea. Most actual card draw in Modern is very slow or has a drawback. Actual card draw means you actually net cards, not just trade one card for a different (which is called a "cantrip"). The best card draw engine in Modern is Dark Confidant
, but he's $50 a copy and you have to have a deck that plans on killing the opponent really fast so the life loss doesn't matter.
Grapeshot: Look at the decklists for the Strom combo. Here's a series of plays they could do about turn 3 with 4 cards in hand: Desperate Ritual
, Seething Song
, Gitaxian Probe
, Serum Visions
, Desperate Ritual
, Seething Song
, Desperate Ritual
, Past in Flames
, flashback all of the spells played before, Grapeshot
with 19 copies. The deck is entirely mana (rituals, lands), card draw (Probe, Vision, Manamorphose) and kill conditions (Past in Flames, Grapeshot, Empty the Warrens
). The deck could kill you on turn 1 or 2 if the "good" rituals
Splinter Twin/Kiki-Jiki: They might disapper, but when you combine it with Deceiver Exarch
, Restoration Angel
(Kiki-Jiki only), Village Bell-Ringer
, you can create an infinite number of tokens and swing for the win that turn. A dedicated U/R Splinter Twin deck will be able to do this on turn 4 (end of your turn 3, flash in Exarch, untap, play Twin, make infinite copies and win). A G/W/U/r Birthing Pod deck can do it on turn 3-4 with a very long Pod chain.