Banning strategies

The ban list seems to be nearly locked in in many games. Invariably, it goes like this:

Bans: Shen, Blitzcrank, Malphite, Amumu, Darius, Elise...

There's a bit of wiggle room on Elise and Darius but in 90% of the solo queue games I've played, the first four are dependable. Why is this?

First, there's insufficient time to talk about who you want to take to make targeted bans. If I want to play Heimerdinger mid, Lux is a must ban. But there's not time to do that.

Second, the champions above are probably the "swingiest" champions in the game. Shen allows split pushing that requires good communication to counter. Blitzcrank only needs to land one hook to completely change a game. Malphite's ult is the best initiate in the game, hands down. Amumu's is only slightly behind him. Darius is widely considered OP against less experienced players (i.e. us lowly bronze leaguers). Elise is a bit of a strange case but has % health damage for both current health and missing health so presents a good choice in the current meta.

But I wonder why teams don't pay attention to who's picking first before doing this.

When I have the lead pick, I invariably pick Elise first. She's good in the meta and it doesn't tip my hat. But once my opponent starts picking Shen/Blitzcrank/Malphite/Amumu, I'll often pick other picks. They can only ban one of those four and we've got first pick. What the other team SHOULD do at this point (and they don't often) is to stop banning the conventional picks. Once it's clear that I'm going to force them to give us a good pick (once I ban Nidalee, for instance), they should ensure they get a good pick second and third. But they rarely do this. It doesn't happen often, but you can frequently get yourself one of the "premium" picks without giving up any. The worst that can happen is that they get one and you get one but I've found that to be rare. In fact, I've played a number of times where we got two of the top picks because they lacked the champion pool / knowledge base to switch champions around. So maybe they had Amumu but either weren't good with him or their jungler was picking last and no one could switch. So we got Blitzcrank and Amumu...

Anyways... Pay attention to your bans.