Introduction

This is my first guide
I hope you guys like it
Replays

If you want to see me in game. :D
Uses LoLReplay which you can get here
http://clgaming.net/replay/55
http://clgaming.net/replay/109/
http://clgaming.net/replay/280
http://clgaming.net/replay/289
http://clgaming.net/replay/352/
http://clgaming.net/replay/374/
http://clgaming.net/replay/918
Quick Build

Quick build for those who need it fast.

I use typical physical masteries: 21/0/9

Summoner abilities: Ghost and Ignite
Items: (average item build)
[builder=Blitzcrank/83f94d66ff8d1455e4015239354a71f1]
Runes:
Greater Mark of Desolationx9
Greater Seal of Evasionx9 or Greater Seal of Clarityx9 or Greater Seal of Resiliencex9
Greater Glyph of Shieldingx9 or Greater Glyph of Clarityx9
Greater Quintessence of Fortitudex3 or Greater Quintessence of Fortitudex2 and Greater Quintessence of Desolationx1
Masteries + Runes

masteries:
21/0/9
Get improved masteries for whatever summoner spells you get if it fits into mastery tree without totally changing it

runes:
Greater Mark of Desolationx9
Greater Seal of Evasionx9 or Greater Seal of Clarityx9 or Greater Seal of Resiliencex9
Greater Glyph of Shieldingx9 or Greater Glyph of Clarityx9
Greater Quintessence of Fortitudex3 or Greater Quintessence of Fortitudex2 and Greater Quintessence of Desolationx1
Items

Build order
Doran's Shield or Sapphire Crystal
Get Doran's Shield if you have mana regen runes and know how to conserve mana well.
Get Sapphire Crystal to get Sheen more quickly or if you don't have mana regen runes.
Sheen
Boots of Speed
Phage
Mercury's Treads or Boots of Swiftness
Trinity Force

If you don't do good in the start you can get Philosopher's Stone early, and then upgrade it to Eleisa's Miracle or sell it later on.
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Good Items to have:
Banshee's Veil great for blocking nasty spells like ashes ultimate
Randuin's Omen allows you to fight enemy physical champions more easily
Frozen Mallet (for guaranteed slow and hp)
Infinity Edge good for if u like criting
Phantom Dancer even more movespeed and more crits (and goes well with IE)
The Bloodthirster great for pure damage instead of getting IE
Frozen Heart same reason as randuin's, but it gives mana instead of an AOE slow
Hextech Gunblade gives same flat damage as The Bloodthirster, while also giving more flat life steal, ap, spell vamp, and i useful active. This item is great instead of a The Bloodthirster if you dont farm that well or if you are dieing a lot. Thanks to Sarras for the suggestion
Moonflair Spellblade gives ability power and tenacity which is useful if you didn't get Mercury's Treads
Eleisa's Miracle gives hp regen, mana regen, and tenacity which is all useful.
Cloak and Dagger gives attck speed, critical chance, and tenacity which is all useful for blitzcrank

NOTE: TENACITY DOES NOT STACK

This is what it should look something like:
[builder=Blitzcrank/83f94d66ff8d1455e4015239354a71f1]

If you want my ap build it is here:
[builder=Blitzcrank/39b3aca4e656e9e2f93a47e73d980ba3]

Also if you were looking for my old attack Blitz build here it is. On attack blitz i think Manamune with Frozen Heart would be great for him.
[builder=Blitzcrank/b28c3abe6ddd60f392606a8f0d8eda78]
Skilling Order

Prioritize
Static Field - Rocket Grab - Power Fist - Overdrive
Summoner Abilities

Ignite - This spell is good for getting those guys who barely escape or messing up someone's health pot
Teleport - This spell can be used to get back to lanes quicker in case an enemy is coming and so you don't lose as much xp
Flash - This spells is good for chasing or running away
Cleanse - This spell is good in case you get they have a lot of CC and Mercury's Treads can't handle it
Exhaust - Great spell, reduces armor, MR, and slows get this instead of ignite if u think it is better
[spell=Fortify] - Great move for any tank, it allows you to save turrets and the increase in attack speed on the turret when you use it can even get a turret diver killed
Ghost - same reason as flash but it has shorter cool down and you cant go over walls
Clairvoyance - great spell to find enemies in the bush and to scout baron and dragon

I prefer using Ghost and Ignite
Tips & Tricks

Blitzcrank's ultimate Static Field now silences for 0.5 seconds so if they have more than one channeling champion you just use Static Field and cancel them. Example: they have a kat and a nunu ulting, you just use your ult and they're out.

Rocket Grab can be used to pull into turrets (which you probably all know, maybe even from getting pulled into one), you can also use Rocket Grab to pull a turret hugging enemy champion out of the turret to kill them when they think they are safe.

Power Fist is not only just for using after your Rocket Grab, it can be used to flee also, you can do this by running into the grass then when they come in use Power Fist, this will make you about the same distance away as if you just kept running but this will also bring their health down, making it so that if you repeat this process they will get low and you can kill them with Rocket Grab and Static Field
Early Game

This is levels 1-5:
First Blood:
You can probably get first blood either before or a little after minions spawn with your lane partner by grabbing a squishy. If you can't that's OK.

Laning:
After your first blood you should try to farm unless they are harassing you if you try to. Remember to always grab an enemy champion when you can, this is for harassing, make sure your lane partner is helping to, because you may end up getting a kill.
Mid Game

This is levels 6-14
Team Battles:
This is where team battles start happening. You need to initiate for your team by grabbing a squishy and kill them with your burst. Doing this will provoke the enemy to attack usually and it will be 5vs4 because one of them is already dead, giving your team the advantage. Make sure that you are tanking for your team, but also remember you are not the main tank, you are the off tank

Pushing/Laning:
As Blitzcrank your ultimate can destroy lots of minions, so if there are lots of enemy minions built up going to attack your turret, just run in and ult, as your ult has a very short cooldown. DO NOT PUSH USING ULTIMATE. when you push just basic attack and power fist, the passive on your ult will take down the minions. When you get to a turret use overdrive and powerfist to take it down.
Late Game

Levels 15-18
Team pushes:
Your team should be doing team pushes by now. In these you can't do much, but they often lead to all 5 enemies standing next to a turret, this usually starts as a team battle in which you initiate with your grab so the turret cannot help them as much.
Lane Partners/Enemies

Great Partners for Killing Enemies at Your Turret (Blitz is great with everyone):
Alistar, you pull, Alistar stuns and knocks into turret!

Amumu, you pull into turret, Amumu ult!

Gragas, you pull, gragas ults enemy into turret

Heimer, Pull enemy into turret mass! Then heimer ults, slowing enemy

Janna, Howling Gale into minions, enemies move out of minions, you use Rocket Grab, Janna uses Monsoon and pushes them into turret

Malzahar, Pull into turret then Malz ult!

Morgana, you pull into turret then Morgana uses Dark Binding

Poppy, Pull then poppy runs them into turret which also stuns

Rammus, pull into turret then rammus taunts

Ryze, You pull, Ryze snares

Shen, same reason as rammus

Singed, pull then Singed throws into turret

Vayne, same reason as poppy
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Enemies:
Squishes=DEAD
Tanks=maybe dead

Its as simple as that
Pros/Cons

Attack:
Pros:
Good burst and good constant
High survivability
Higher movespeed than AP but less than old attack
Lots of slows
Good at initiating
Good amount of mana but not as much as AP

Cons:
Blind shuts you down
Not as much burst as AP

AP
Pros:
High burst damage
Good amount of health for tanking
Enough mana so you don't run out
Great for initiating (just don't pull a tank to start team battle)
Good at chasing (but you need a partner to do the damage)

Cons:
After burst damage, your a lot weaker
Slow so its hard to run (unless you got Overdrive early)

Old Attack:
Pros:
Good burst damage and good constant damage
Higher movespeed than AP
Can initiate well
Great turret destroyer

Cons:
Low mana
Not very tanky
Any blind shuts you down
Images