The Bird is the Word: Tips on Using Articuno in Ultra League

(This is a copy paste of a reddit post I made on TheSilphArena, saved in this form for posterity. It's also my first foray into writing about Pokemon Go PvP.)
I started Season 1 Ultra League at Rank 8, 2017 rating, and after going 157-102-1, I made it to Rank 9 with a 2510 rating. 60% win rate, or 3-2 sets, doesn’t seem like much, but positive is positive, allowing me to rank up when I was basically treading water at the end of Great League. Anyway, here’s Wonderwall--I mean my team:

Articuno (Lead)
(Shadow) CP 2494, 5/10/13, Ice Shard, Icy Wind, Ancient Power
(Regular) CP 2496, 11/11/14, Ice Shard, Icy Wind, Hurricane
Swampert CP 2490, 0/11/15, Mud Shot, Hydro Cannon, Earthquake
Registeel CP 2401, 14/12/12, Lock-On, Flash Cannon, Focus Blast

I ran the Shadow Articuno from the beginning until the Ancient Power nerf, then switched to a legacy version with Hurricane. The Swampert is a decent stat product that will lose the mirror CMP, but that’s okay since I usually line up Articuno against opposing Swamperts. The Registeel is pretty bad, but it was a lucky, so I maxed it, and it still goes to work doing its Registeel things (beep, beep, beep).

Like any lead Pokemon, Articuno has good matchups (Giratina, Togekiss, Grass types) and bad matchups (Steel and Fire). What makes it such a powerful lead is the way it plays in the neutral part of the field. These are matchups where the outcome isn’t obvious based simply on type advantage, and in some cases, the typing may be unfavorable (looking at you, Poliwrath with its Ice resistance). And yet, Articuno can come out ahead in these matchups, giving you the switch advantage, and overall control over the way the rest of the game plays out.

Shield the first move
Swampert, Poliwrath, Snorlax, Clefable, and Alolan Muk are all favorable matchups in the 1v1 shield scenario, but it’s important to shield the first charge move, especially if it comes out before the Icy Wind. Any subsequent charge moves will be debuffed, so shielding the opening charge move will save you the most HP, giving you more play in the mid-game. Yes, even against Snorlax and its relatively weak Body Slam, shielding that first 35 damage is the difference in the 1v1.
The key to this strategy is to win the switch advantage in these neutral leads, even at the cost of losing the shield advantage (but only going down 1 shield). Between Swampert and Registeel, I have most of the rest of the field pretty well covered, and in some of the most common back-end matchups, I can win with a 1-shield deficit (Swampert vs. Registeel and Registeel vs. Giratina), so it’s just a matter of staying in a favorable matchup. It might be tempting to switch out your Articuno and bank an Icy Wind for later, but it is usually correct to just let it go down to maintain switch advantage.
If they switch out, there’s a quick decision to be made. For safe switches like Snorlax, I generally just stay in with Articuno and follow the 1-shield strat. The exception might be if their lead was a Grass type. Since Swampert has such a bad matchup there, I want to bring it in against their safe switch to get some use out of it. In that case, I might not shield the first Body Slam, but leave the Snorlax with a parting Icy Wind before bringing in Swampert to save some damage.

Be patient
If you watch your respective HP bars, it often looks like you are losing as you will hit yellow first. Be patient and trust in your Icy Wind debuffs. Many matchups turn in your favor after the second one takes effect. Playing with Articuno is a test of wills. Run through a couple of common matchups on PvPoke.com to reassure yourself that you can win these matchups. For me, Poliwrath was one that I kept switching out of until I ran the 1v1 sim and saw that it favored me (and that was before using Hurricane instead of Ancient Power, which makes the matchup even easier).
The come-from-behind aspect of Articuno’s wins can also have a psychological effect on your opponents, as they notice they are starting to fall behind in the damage race. This can result in panic shielding, as they try to get off one more charge move on you. This is great for you. As I said, you still win most neutral matchups in a 1v1, and they are using their shield to launch a heavily debuffed charge attack that does little damage and still won’t flip the lead. Heck, in some of these matchups (Swampert, Snorlax), you win even if they shield twice and you only shield once. That’s how deceptively powerful Articuno is.

Stand back; there’s a Hurricane coming through
For most of the Ultra League, I’ve used my Shadow Articuno with Ancient Power. I liked that the shadow bonus flipped a few matchups in my favor (Armored Mewtwo being the most notable). When Ancient Power got nerfed, it was overall good news for Articuno, since the Giratina Altered matchup got a lot easier, but I also lost my best weapon to fight back against Charizard. The day of the nerf, I powered up a legacy Articuno with Hurricane and tested it out. The move doesn’t come up too often, but the one place where it made a huge difference was against Poliwrath. This used to be real tough. As I said, I was actually switching out because of the Ice resistance. Even staying in, the matchup is a slog that leaves you with no HP or energy.
Until I tried Hurricane. It’s almost a One-Hit KO with the Ice Shard chip damage. However, I think charging up to it as your first charge move is a mistake. Poliwrath players who know the timing of your Icy Winds will smell this from a mile away and shield. My preferred play is to use an Icy Wind first (still shielding their first charge move). I’ve never had anyone shield the first one. You can even overcharge by one Ice Shard to throw off their move count. The Icy Wind will still connect before their second charge move. Then tank their second charge move and launch the Hurricane. I’ve done this four or five times now, and thus far never been shielded, coming out of the matchup with almost half of my HP.
It’s possible that there are other situations where a surprise Hurricane will do some work. But for now, just the way that it has turned my Poliwrath matchup into an easy win has been worth it compared to the number of times Ancient Power did anything (I killed a Charizard once…)

Taking the L
“But you lose to Fire and Steel leads.” Yes, I sure do, although I have had hard-fought wins against both, by and large, those are likely losses assuming they have a Grass-type to eat my Swampert after I switch. This is the reality of the meta, and despite all the conspiracy theories about the pairing algorithm, by keeping track of all my matchups, I can tell you that I’ve faced a Fire or Steel lead 52 times in 262 Ultra battles to date (not counting Steelix, which is actually neutral due to its Ground typing). Over that same period, I’ve faced 51 Giratina Altered, Togekiss, and Grass leads, the things that I would consider to be hard-countered by Articuno (Giratina matchup was a bit more difficult before the Ancient Power nerf, but still favorable albeit requiring matching shields--now it usually induces a switch).
So yeah, don’t fall into the confirmation bias when you happen to face a Charizard and a Registeel lead back-to-back. Keep track of your matches and look at the big picture. For Articuno, the hard losses and wins have evened out for me, I have found ways to win the soft middle ground, and a good team to deal with most of the back, which is how I’ve (slowly) climbed up the ranks.
You will have bad luck where you run into fire and steel 3 times in a set of 5. You can panic and change your lead, then cry “conspiracy” when you start facing Venusaurs with your Swampert lead, or you stay the course, trust the regression to the mean, and Ice those Grass leads.