Blitzers are arguably the most important players on the Orc roster. Blitzers are the real go-to men of the team - they run, block, tackle and do much of the leg work. Black Orcs are the engine room of the team - but normally they provide the primary blocking. Blitzers on the other hand do pretty much anything and everything. They have good progression options and they are cheap compared to many equivalents. For example a human Blitzer costs 10k more, but is identical part from swapping +MA for +Av. Wights are 10k more and have regen but Av8. As such its very rare to see Orc teams without all four, including most starting rosters.
One of the big upsides of Orc blitzers is their general and strength skill access. Easy access to Tackle, Guard, Mighty Blow, Piling On, Frenzy and Stand Firm give lots of good development options. The all round nature of the position, and wide selection of development choices actually make Blitzers extremely versatile and hence the wide variety of choice can make it hard to develop cohesive players let alone teams. The all-rounder role also means that all stat increases are good and worth taking even on rookie players.
To Dodge or not to dodge, that is the question
Before I delve into the details of the different build options I think its worth having a little side discussion on choosing dodge. Most teams will have a couple of tackle players, and dwarven teams have many more. So there is an argument that one or two dodge players - particularly on S3 players - just give your opponent's tackle players something to do. Other double choices might not be quite as good as dodge on an individual basis but they do make that TV invested in tackle a waste and hence can give an advantage to you. As such a good rule of thumb is early on in the team's development decide whether to take dodge on doubles or not. If you do decide to take dodge then take it on everyone who rolls a double (at least all the Throwers, Line Orcs and Blitzers) or decide not to and give all the Line Orcs and Blitzers other skills instead. Throwers built to be runners should take dodge regardless - but they should be the only exception. If you want to go with a goblin heavy team then its a good idea to take dodge everywhere else too.
I've crudely broken the build types down into the categories below. There are lots of subtle variations around these, but hopefully it will give a good idea of styles of Blitzer to build. One of the styles is called blitzer and I've used the capitalised version of the word to indicate the position rather than the style. Generally speaking the styles have relatively short progression paths - two or three key skills. At this point Blitzers tend to switch development into one of the other styles so you will end up with a mix of the styles on a fully developed player. In terms of frequency of style selection my personal preference is for an initial mix of guarders and blitzers, with other styles coming later in development. Its always worth bearing in mind that keeping the right balance of skills on the team is important. So you might be light on tackle for instance and need more so encourage that style or build. Or it may be you are being out-muscled and need more guard etc. So don't worry too much about switching styles for a player to help the team out as a whole.
Guarders generally are focussed on helping Orcs win the bashing war against other strength teams. Guard is obviously the key skill here. Getting and keeping sufficient guard on the team to have a large number of 2 dice blocks in your favour, and minimising the opponent's ability to do the same is how Orcs really win the bashing war. After Guard there are several good options - stand firm ensures annoying Guards stay where you want and Mighty Blow is good since these players will often be in the thick of the fray and making blocks themselves. On doubles, dodge is the obvious choice, but if you've decided against dodge then sidestep can be an interesting alternative to stand firm. I'm not convinced its worth the 10k higher cost on a guard player since more often than not they'll already be in the right place. Otherwise doubles would probably trigger a switch to a different build style.
Killers are pretty straight forward for Orcs. Mighty Blow and Piling On are the two skills available that naturally increase the injury rate. Although Piling On is mathematically slightly better than Mighty Blow for generating casualties Mighty Blow keeps you on your feet and hence is a better choice. These two skills are often augmented with skills to improve the knockdown rate - tackle and frenzy being the obvious choices. On doubles Jump Up is a powerful method to counter the negatives around Piling On. With those skills in place then then most of the other styles work well except for runner. In mature Orc teams I'd expect most if not all of the blitzers and Black Orcs to have Mighty Blow by their 4th skill. That makes specialist killers (with piling on) used more for targeted hits rather than general mayhem.
As the fastest player on the team it is natural for Orc coaches to use Blitzers to run the ball. There are build styles for the team which don't bother with Throwers at all and emphasise a pure running game using one or maybe two blitzers in the role. Runners take Sure Hands to help with pick ups and neutralise Strip Ball (particularly from War Dancers and their ilk). After this the options for normal progression aren't too obvious, although Fend is a handy skill on any ball carrier - although if you intend to take stand firm in the future on this player then the benefit is slight. Doubles - dodge is very obvious even if you have decided against dodge (in which case though you probably won't take dodge on any throwers). If you still don't want dodge then catch or nerves of steel can be useful.
Funnily enough the basic role type is one that Blitzers are pretty good at. The key skills here are Tackle and Strip Ball. Tackle is a great skill for both knocking over blodgers and for marking opposition receivers. Strip Ball I'm not a massive fan of on Orc blitzers, but can be useful in leagues where the main threats either don't have sure hands on the team or as a last line of defence. After those skills Mighty Blow is the next obvious choice since it makes those hits a bit more damaging. Frenzy is another option to give a 2nd bite at the cherry and can be tactically very useful for opening defences and working the sidelines. Frenzy is also good as an alternative to Tackle to bring down those annoying blodgers - whilst not tying up TV in a skill that might not be widely useful. I really like Frenzy on +ST Blitzers where you are far less likely to get into trouble, but with some guard and intelligence it should rarely cause a turnover. In low skill environments Frenzy is a good alternative to tackle and does not have the problem of only working against dodge players.
Pro, Wrestle and Juggernaut are in the second list of teams. Pro gives about 10% more knockdowns on a 2 dice block which can be handy. Wrestle enablers you to put Block players prone - which could mean getting the ball loose or making that vital whole. Normally I wouldn't recommend wrestle on a block player but for specialist blitzers its a worthwhile option. Juggernaut is useful for cancelling fend, wrestle and stand firm as well as generating more pushes.
I'm in two minds about whether this is a specialised version of a guarder style or not. Some Orc coaches really like Stand Firm as a great positional skill. If your opponent can't push you out of the way then it can be very difficult to break down the defensive line to score. From Stand Firm there are two obvious directions - Guard or Tackle. Guard just goes straight into the guarder role with the variation being Stand Firm came first. With Tackle, and Diving Tackle on doubles, you have a player who not only is hard to shift but against agility teams is difficult to move out of the way and difficult to get away from. Roadblocks are also very handy if you want to fight a sideline war with frenzy-heavy teams as having some one who can't be moved is handy. Remember though that Juggernaut negates Stand Firm.
A variation on the roadblock style is a marker, and especially in leagues where passing teams represent a significant threat, is to add Pass Block as a later skill. A couple of block, tackle, diving tackle, stand firm, pass block Blitzer can significantly reduce the passing options for some teams. Notice that Pass Block is to shut down channels for the passing game, not really to create interception attempts. Normally the threat of an interception is enough to make many coaches avoid providing the opportunity - but hopefully you'll force a riskier play than they'd need to otherwise.
This really is very obvious for me. +ST makes them awesome ball carriers and blitzer types. With an early +ST I'd either go for a runner or blitzer build. With a blitzer build I'd make Frenzy a priority since MA6 S4 Frenzy players are very useful. Then I'd probably be focused on killer skills since you'll be hitting with him a lot.
Agility is fantastic on Blitzers, arguably having a bigger impact on the team than +ST would. Having a player who can reliably dodge and handle the ball is great and helps provide options that otherwise the team wouldn't have. +AG continues their all-round role a bit since they work well as blitzers and runners. There is now an option of developing a receiver too. However lack of Agility skill access means unless you get doubles skill choices are limited.
Another option to consider on doubles for a +AG player is Leap. Orc teams don't normally have it, and a 3+ leap with a one dice hit is actually a pretty reliable method of getting the ball free. Even if it doesn't just the threat of the leap can make your opponent more cautious and allow you to stop the drive by more conventional means.
There is one very handy skill on +AG Blitzers that does not normally recommend itself. Pro is a bit of a marginal skill for many players but AG4 players without agility access benefit from it quite a lot. The ability to try to reroll any agility roll is very handy when they will often be on plays when you'll have used a team reroll already or you might not want to exhaust it on a non-critical action.
On a 6,4 I'd almost always take the MA. Speed is one of the main weaknesses of the team, so adding to it is always handy. As with every team adding MA to your fastest players is always a good - they are the ones you'll often be moving furthest anyway. Also the transition MA6 to MA7 is significant for making 2 turn TDs doable without any GFIs. Once you've got MA7 (or 8!) then blitzer and runner builds emphasise the advantage most. If you've already developed as a roadblock or marker you may even want to consider Shadowing to compliment Tackle & Diving Tackle. I wouldn't normally bother with it on anyone with MA6 or lower, but at MA7 it starts to become more useful.
+Av in contrast makes them even tougher. Since you've already got Av9 you are already pretty tough, and Av10 does not help against Claw. However if you've already gone a way down a guarder build then it might be a good option, but generally speaking MA is a better choice.
5,5 does offer a lot of alternatives, but all other things being equal I'd tend to prefer MA over any other choice. Speed is the biggest weakness of the team, so speeding up the fastest players really helps. This is marginal though, so a lot would depend on league composition and the current status of the squad and player.
As you can see Orc Blitzers have a huge variety of options in terms of development. For me bread and butter skills are Tackle, Mighty Blow and Guard. With tackle the team probably wants two fairly early on and at least four longer term. Line orcs (with Wrestle/Tackle) can fill that quite effectively leaving other options for Blitzers. Similarly with Guard the key is having enough so that you can dominate other bash teams. So if Black Orcs all have Guard then its less important on Blitzers. Mighty Blow is wanted on all the Blitzers by fourth or fifth skill IMO since you need a certain lethality across the team to compete with other bashers - even if you've got a guard advantage.
With all the options its easy to end up with players and teams that aren't cohesive but with some thought and planning its not too hard to build a formidable array of Blitzers that let you take on even the most difficult of match ups.