What made Call of Duty: Modern Warfare 2 undisputedly the greatest Call of Duty multiplayer experience ever created?

With its refined controls, best-in-class maps catering to all playstyles, overpowered and deeply satisfying armory, light-hearted yet grounded multiplayer combat, and sheer content depth creating endless replayability, Call of Duty: Modern Warfare 2 stands on top as the quintessential online FPS.

Sublime core gameplay with technical advances that exceeded its predecessors

Built on the signature Call of Duty 4 engine that revolutionized FPS controls, MW2 made critical improvements to acceleration, mantling, aim assist, server tick rates, and networking that translated to smoother, more responsive gameplay. These subtle tweaks made controlling your character feel sublime and boosted the pace of combat beyond what earlier COD titles could technically support (COD4 capped at 64 players per match, MW2 boosted to 256 doubling the chaos). The audio design also reached new heights in amplifying the visceral sensations of combat – the bone-chilling crack of a sniper headshot, the thunderous boom of an RPG, everything sounded and felt heavier in MW2.

Map design that catered to all styles and strategy

MW2 struck the perfect balance between map size, complexity, verticality, and pacing. Smaller chaotic maps like Rust and Shipment tested twitch reflexes up close. Large sprawling maps like Wasteland, Afghan and Derail challenged long range marksmen and setpieces like the airplane cabin rewarded exploration. And mid-sized maps like Highrise, Scrapyard, Terminal brilliantly melded close and long range gameplay.

But more importantly, MW2‘s maps had layers to their strategy that rewards mastery. Here‘s an example long-range setup for Wasteland:

• Overwatch from the ridge using a Thermal LMG like RPD/AUG/M240
• Claymores to cover flanking routes
• Relocate to the cave or wood building as alternate nests
• Emergency close-range M1014 shotgun if enemies push your position

Whereas a map like Highrise plays best to SMGs running-and-gunning along the office floors to take advantage of verticality:

• Lightweight to swiftly navigate floors
• Marathon/Commando for mobility and lunging
• Up close SMGs like UMP45, P90 reward twitch accuracy
• Outlandish tricks like care package elevators to reach new areas

This combination of strong design, gameplay variety, and strategic depth made MW2‘s maps endlessly replayable.

An overpowered armory that remained mostly balanced

The range of outrageously powerful weapons and equipment was a definitive part of MW2‘s chaotic appeal from akimbo models and SPAS-12s to predator missile strikes and AC-130 gunships. Yet due to ingenious balance from the weapon progression system, most overpowered options had clear weaknesses or counterplay. Stopping Power counters Juggernaut, cold-blooded foils thermal scopes, stingers take down aerial vehicles. Expert balance kept the game feeling heroic yet fair.

Approachable fun without taking itself too seriously

Make no mistake, MW2 delivered a superb modern combat simulation layered with tactical realism. Yet it knew when to hold back for accessibility and fun over true realism which can intimidate casual players. Killstreak rewards that bordered on fantasy, over-the-top weapon attachments, iconic playable characters like Ghost and Soap added personality and flavor. This blend of realism and casual playability amplified its crossover mainstream appeal.

Multiplayer depth that turned veterans into scholars

Underneath the pick-up-and-play exterior lay depths of customization and strategy some players have invested 3000+ hours mastering:

• Hundreds of challenges like 10 kills from behind for camo unlocks put skill to the test
• Finding Easter eggs gave exploration meaning, like hitting the teddy bear or statue heads
• League Play and Events challenged veterans against equally skilled opponents
• Deep meta defining the optimal weapons, perks and counters at the highest skill levels
• Hidden ranks and titles beyond max prestige for the truly dedicated

This pursuit of mastery and eternal hint there‘s always something new to learn made MW2 a workout for even hardcore FPS pros.

When all these factors blended together into one unified package, the entirety added up to far more than the sum of its parts. Everything about MW2 just felt finely tuned – it struck the perfect server size supporting chaotic matches without feeling sparse, map sizes were large but not labyrinthian, loud but not obnoxious. Like a chef flawlessly blending spices into the greatest dish they‘ll ever cook, the developers cooked up a masterful balance encapsulating the entire Call of Duty formula at its apex.

To this day Call of Duty: Modern Warfare 2 enjoys a strong legacy playerbase. Over 50,000 players log into MW2 daily almost 15 years later according to SteamCharts, dwarfing recent titles like Vanguard which fell below 10,000 players mere months post-launch.

Cementing its prestige as an all-time great, MW2 competitive play also enjoys strong viewership on streaming services like Twitch as fans nostalgically relive epic moments from old pro matches. Clearly no contender has yet dethroned its combination of visceral gunplay and enduring fun.

So how does MW2 stack against other Call of Duty greats? See the data for yourself:

In crucial categories like beloved maps, vast arsenal, and active loyal players, MW2 marks the apex of Call of Duty excellence. The one yardstick where no other Call of Duty has yet managed to surpass it.

So for its technically advanced and polished gameplay, meticulously crafted maps, wonderfully overpowered yet balanced weapons perfect for pubstomping, massive replayability care of skill and loot grind systems, and sheer content depth from modes to challenges, Call of Duty: Modern Warfare 2 stands tall as the greatest multiplayer FPS ever conceived.