I'm going to take a stab at explaining/translating some of the examples from that article. The first is about "mana screw". In Magic: the Gathering, each player has a deck of 60 cards, of which about 2/5 are "land" or "mana", and the rest of which are "spells". Each turn, players draw one new card, put down one land card if they have it, and play spells whose total cost is less than or equal to the number of lands they have. Costs are typically distributed in a bell curve centered at about 3.5. If a player has too few lands relative to the cost of his spells, he can't play them; this is called "mana screw". If he has too many lands, he won't have spells to play with them; this is called "mana flood". Lands and spells also have color; to play a spell, some number of the lands used must be the correct color or colors.

At the start of the game, each player draws 7 cards, looks at them, and decides to either keep them or mulligan, which means he puts them back, reshuffles, and draws a new hand with only 6 cards. (If the 6 card hand is also bad, he can do it again, getting one less card each time.) If the initial 7 cards are worse than average (too few, too many, or the wrong color lands), then the player chooses between a small certain loss (one less card) and an uncertain large risk (you might not draw the lands you need, and be mana screwed). In practice, most players are strongly biased towards keeping hands they shouldn't, which means accepting the uncertain large risk over the certain small loss.

The second issue is "netdecking". Players can either choose the cards in their deck themselves, or get a deck from the internet, usually by looking at a recent tournament and copying the winner's deck, or if they're really serious about it, guessing which decks they're likely to face, choosing a pool of candidate decks, looking at win/loss statistics, and choosing the deck which gives the best chance. Copying a deck that's known to win is much more effective, but making a deck yourself is more fun. As a convenient side-effect, making your own deck gives an excuse for losing.

The third issue, which the article alludes to but doesn't tackle directly, is that MtG involves a large number of easy decisions, with a small number of hard decisions mixed in but not clearly labeled. Players who think too long about all of their decisions are chided for stalling; on the other hand, players who fail to slow down and think will often lose the game because of doing so. Most players can't tell the difference between a hard decision that requires thought, and an easy decision that can be made quickly; instead, they make all decisions quickly until they know they're on the verge of losing; then they switch to thinking carefully about every decision, but at that point it's usually too late.