StarCraft 2 forcing a game that keeps army sizes smaller

What I'm wondering is: if anyone can suggest a strategy to keep the game from becoming about building an overwhelming Army, but instead about smaller (and perhaps simultaneous) engagements?

After watching some VODs online I've noticed that army sizes increase as the game progresses. Which makes sense, because as the economy of each player increases they are able to produce more and more units, and build more and more structures (or have built more structures).

I think I see smaller Armies in the Pro games (anybody agree with that?). (Yes, eventually one force gains enough of a lead to make the large, overwhelming army -- and it usually is near the end of the game).

Fight early, fight often.

Focus on map awareness. Building big armies requires big resources that have to come from somewhere. Harass your opponent as he tries to expand, forcing the smaller skirmishes. Limiting resources is the best way to force combat with less troops.

I agree with Toast's answer.

I'd like to add that the larger all-out maxed army battles you commonly see are also an artifact of the maps that are currently used in ladder.

The current ladder maps feature the following traits that lead to large macro games,

• Main base is on high ground
• Main bases are at the edges of the map and far apart from each other
• Narrow ramp leading to main base
• Close natural expansion
• Easy to defend choke in front of natural expansion
• 3rd expansion close to main base
• Has a high number of extra expansions

I looked for counterexamples to these traits in current SC2 maps, but I couldn't find any. So please bear with the Brood War examples =P

Andromeda (2008)

Meet "Andromeda"; this is a macro map. Games generally lasted 40+ minutes.

• Main base is on high ground ✔
• Main bases are at the edges of the map and far apart from each other ✔
• Narrow ramp leading to main base ✔
• Close natural expansion ✔ (It's in your main)
• Easy to defend choke in front of natural expansion ✔
• 3rd expansion close to main base ✔
• Has a high number of extra expansions ✔ (7 for each player)

Throw in the vast openness of the center of the map, and this map was perfect for defensive play. The games focused on denying and trading expansions.

Bifrost (2002)

Say Hello to "Bifrost"; this is a micro map.

• Main base is on high ground ✘
• Main bases are at the edges of the map and far apart from each other ✘
• Narrow ramp leading to main base ✘
• Close natural expansion ✔/✘ (There's a mineral-only behind the main. But to get gas, you had to stretch)
• Easy to defend choke in front of natural expansion ✘ (It has two routes of attack; and one route is from the high ground! Commit to defending your natural, and your main is vulnerable)
• 3rd expansion close to main base ✘ (It's the same land distance to the 3rd gas as to your opponent's door)
• Has a high number of extra expansions ✘ (2 with gas for each player)

Never had the pleasure to see a game on this map (was before my time). But just looking at the attack routes and limited gas on the map, I'd guess that it was rare to see maxed armies or even tier 3 units on this map.

It's helpful to think about what playstyles the maps will inherently favor.

SC2 is a good simulation of the cold war: It's not that you'd want to build a big army, but you want your army to be bigger the other guys, in case he attacks. So it's usually a race towards the 200/200.

The pro players have smaller armies, because they know exactly how many (or, rather, few) units they need to be safe at any point in time. Pro players prefer to invest their resources into tech, to get more effective armies a bit later. And they are able to, since they know what the opponent is doing, and could be doing in the future, based on the limited information they collect throughout the game.

Lower level players don't have the same game sense, so the easiest way to know that you're safe is to build as many units as fast as possible as soon as possible. Well, that's the thought process, anyways.

But: in the end, the win conditions of a SC2 game is "destroy all structures of the opposing team". So, sooner or later, you need an army that can do that, and most often, you need to go through the enemy army at one point or another.