At Pro Tour 25th Anniversary, the breakout deck in Modern was B/R Vengevine. With the printing of Stitcher’s Supplier in Core Set 2019, the deck gained a creature that could not only mill over Bridge from Below or Bloodghast but also bring back Gravecrawler or Vengevine.

B/R Vengevine

Jacob Nagro, 7th place at Pro Tour 25th Anniversary

The deck is capable of explosive starts. For example, you could play Faithless Looting on turn 1, discard Bridge from Below and Vengevine, follow up by casting two Walking Ballistas for 0, and pass the turn with 8 power on the battlefield. That’s an insane first turn, but the strategy is vulnerable to certain sideboard cards.

If you have Leyline of the Void in your opening hand, then you don’t have to worry about opposing graveyard shenanigans for the remainder of the game. It doesn’t even cost you any mana!

So let’s run the numbers on this enchantment. Of course, the numbers are the same for, say, Leyline of Sanctity against Burn decks.

Opening Hand Math for Leylines

By combining hypergeometric distributions, you can determine the probability of drawing a Leyline in your opening hand for a 60-card deck.

P[Leyline in opening hand] Always keep 7 Willing to mull to 6 Willing to mull to 5 Willing to mull to 4 Willing to mull to 3 Willing to mull to 2 Willing to mull to 1
1 Leyline in deck 11.7% 20.5% 27.1% 32.0% 35.4% 37.5% 38.6%
2 Leylines in deck 22.1% 37.1% 47.2% 54.1% 58.6% 61.3% 62.6%
3 Leylines in deck 31.5% 50.4% 62.0% 69.2% 73.7% 76.2% 77.4%
4 Leylines in deck 39.9% 61.1% 72.8% 79.5% 83.4% 85.5% 86.5%

The first column represents the probability of drawing a Leyline in your opening 7. If you run 4 copies in a 60-card deck, then your opening 7 will contain at least one Leyline 39.9% of the time.

If you are willing to mulligan down to a certain number of cards in search of a Leyline, then the odds go up. For instance, if you always mulligan any 7-card or 6-card hand without a Leyline, but always keep any 5-card hand, then this corresponds to the “willing to mull to 5” column. Under this strategy, a four Leyline deck will begin the game with a Leyline on the battlefield 72.8% of the time. That is high, but it does require some very aggressive mulligans.

Looking at the numbers, I think that a willingness to mulligan down to 6 may be worth it when you run 3 or 4 copies and Leyline is really good in the matchup. This is a bit of a simplification, since you should keep your best 7-card hands without Leyline, but it’s a helpful way of thinking when building your sideboard. Either way, I would be hesitant to toss back reasonable 6-card hands, and I wouldn’t bother with aggressive mulligans if I only run one or two Leylines.

Unusual as it may be, I don’t mind running Leyline of the Void as a 1-of in my sideboard. As I described in a recent article, the first copy of any card is always the most valuable one. Sure, you can’t craft an aggressive mulligan strategy around a singleton Leyline (which is part of the reason why many people run it as a 3-of or 4-of) but that’s not a must. If you run a singleton Leyline, then at least you’ll never draw multiples and you gain more sideboard slots for other matchups.

Should I Run Rest in Peace or Leyline of the Void?

Leyline of the Void is amazing in your opening hand, but Rest in Peace—the other main graveyard hate card in Modern—is a much better draw later on as it’s cheaper to cast and comes with a relevant enters-the-battlefield ability. To decide which one to run, ask yourself the following questions.

Do opponents have Engineered Explosives? Decks like Hollow One, Ironworks Combo, or Mardu Pyromancer often have Engineered Explosives against you after sideboard. I noticed that this was particularly an issue when I was playing Affinity against Ironworks Combo. I would be pressuring them with Vault Skirge and Cranial Plating while controlling Rest in Peace and Damping Matrix to disrupt their combo… and then they would sweep my board with a single Engineered Explosives. If that Rest in Peace had been a Leyline of the Void, then a disruptive enchantment would have remained.

Can you ever cast Leyline of the Void? A W/U Control deck, for instance, doesn’t have any black mana sources, so if a W/U player ever draws a Leyline of the Void, it’s a dead card. For those decks, I would recommend Rest in Peace. Note that you don’t necessarily have to be able to cast Leyline of the Void consistently since it’s the back-up plan, I don’t mind running it in an Affinity deck with 12 black sources.

How many cards do you expect to draw over the course of the game? The shorter you expect the game to last, the better off you will be with Leyline in your deck. The reason is simple: if you expect to see only 10 cards from your library over the course of an average game, then any graveyard hate you see is quite likely to come from your opening hand. If, on the other hand, you are playing a deck like W/U Control that hopes to play long games, then it’s likely that you’ll draw a graveyard hate card along the way, and then you’re better off with Rest in Peace.

Does Rest in Peace hurt yourself somehow? Rest in Peace is symmetric, whereas Leyline of the Void only hurts the opponent. Even for a deck like Affinity, which seemingly doesn’t use the graveyard at all, Rest in Peace can sometimes hurt you—Arcbound Ravager won’t actually die anymore, which means that its modular ability won’t trigger.

Do you need graveyard hate on turn 1 or turn 2? Rest in Peace can stop KCI or Storm in time. Against those combo decks, a turn-2 Rest in Peace is just as good as starting the game with a Leyline of the Void on the battlefield. Since you have 8 or 9 cards to find Rest in Peace compared to only 7 cards for Leyline of the Void, Rest in Peace is generally preferred. But a turn-2 Rest in Peace is often too slow against B/R Vengevine. I saw many games at the Pro Tour where the Vengevine deck got multiple creatures onto the battlefield from the graveyard on turn 1 or turn 2, so a turn-2 Rest in Peace might already be too late.

Weighing all of the ups and downs, I recommend replacing Rest in Peace with Leyline of the Void in Affinity sideboards nowadays. I was already exploring this because of Engineered Explosives, but the introduction of B/R Vengevine was the final push I needed to make the switch.