Boomerang

It's so classic and iconic and perfect! I honestly wouldn't change a thing on this card -- as a player. As a designer, it's got one critical flaw: it bounces land. In the long game, bouncing a land is meaningless; in the short game, it's just as devastating as a Sinkhole.

Boomerang hasn't proven to be as backbreaking as Sinkhole simply because it's not in a color that got a saturation of easy hand disruption and land destruction. As proof, I offer the following story: During Ravnica-Time Spiral Standard, I played combo du jour Dragonstorm. In one game, vs. blue-black control, I had an opponent keep a three-land hand: Island, Swamp and Dimir Aqueduct. On his turn two, I bounced the Aqueduct. On his turn four, I bounced the Aqueduct. I essentially bought four turns for the cost of UUUU broken up over two turns; I don't recall the poor kid resolving a single spell that game. That's an outlier, to be sure, but a solid 1-drop -- like Delver of Secrets in every damned format except Vintage -- can carry the game on that kind of disruption. It's straight-up trivial for a Standard combo deck rocking Gigadrowse to just wipe a deck off the face of the Earth after a start like that.

So, compare Boomerang to Sinkhole in that context -- both force an opponent to lose a land drop. One does it temporarily, but at instant speed, and can hit a variety of targets. The other is buttressed by in-color discard (which can hit other lands -- see Hymn to Tourach) and Dark Ritual. Late game, the Sinkhole doesn't do much for you, and the tempo value of an early Sinkhole has diminished; Boomerang allows you to continue making tempo gains late game as you trade your two mana for your opponent's X mana. (Keep in mind that tempo becomes swingier and less valuable as the game progresses.)

In other words, all other things being equal, Boomerang's actually a better card than Sinkhole. Of course, nothing's in a vacuum; Sinkhole is far better supported by its color's mechanics than Boomerang is, and few games that start with turn 1 Sinkhole/Duress, Turn 2 Hymn/Nantuko Shade end well. That doesn't mean that Boomerang couldn't use a little downward pressure.

Oh, yeah. Regress.

Regress has been offered as a Boomerang variant; that's fine, and it's perfectly fair at three mana. It's also not very good, since it's hard to reap tempo gains at three mana, even in Standard. Regress is more of an answer card than a tempo card; since it merely bounces, it's versatile, but not very good. I consider it a different take on Boomerang rather than an actual descendent. Something like Repeal is actually truer to the original Boomerang -- it's a slight tempo loss, but the card draw makes up for it (and has proven to be very efficient in some formats, like old Extended or the Ravnica Standard it was released in). Against strong 1- and 2-drops in slowish formats -- think 5- to 6-turn aggro kills through disruptions -- Repeal's actually fairly strong, playing a sort of card-advantage-tempo hybrid role.

But look at me, going on like Boomerang is one of my favorite iconic spells. Here's the basic summation: Three mana's too much. Land drops shouldn't be targetable. With that in mind:

Damn you Morningtide! Stealing my glory! ... I guess it's morning glory now, and there's nothing I can do about it.