CS2 Multi-Case EV Comparator

Understanding Expected Value in CS2 Case Openings

Expected value (EV) is a core concept from probability theory that quantifies the average outcome of a random event over many repetitions. For CS2 case openings, EV tells you how much value you can expect to receive per case opened on average. A negative EV (which all CS2 cases have) means you lose money on average over time — understanding how much you lose per case helps you make informed choices.

This tool is particularly useful because not all cases are equally bad bets. Some cases contain high-value Covert or Knife skins that shift the expected return upward, while others are packed with low-demand skins. By comparing EV across cases, you can minimize your expected losses — or at least understand the trade-offs you are making. For a foundational understanding of the probability math, see our CS2 Case Odds Explained guide.

The EV Formula for CS2 Cases

The expected value of a single CS2 case opening follows a straightforward formula. Each rarity tier has a known drop probability (published by Valve in their official CS2 case odds disclosure), and you multiply each probability by the estimated average value of skins at that tier:

Where P represents the drop probability and V represents the average skin value at each rarity tier. The official drop rates used in this calculator are the same rates disclosed under China's loot box disclosure regulations, which apply globally to all CS2 cases.

Why Some Cases Have Better EV Than Others

The drop probabilities are identical across all CS2 weapon cases — a Mil-Spec drop is always 79.92%, Restricted is 15.98%, and so on. What differs is the market value of skins within each case. Cases containing popular Knife finishes (like Doppler, Fade, or Crimson Web), high-demand Covert skins, or skins from discontinued collections tend to have higher average values at each tier. This is why older, rare cases often have better EV than common active drop pool cases — the skins inside command higher prices.

Understanding these dynamics is critical for anyone spending money on case openings. Our CS2 Case ROI Calculator dives deeper into single-case analysis, while this tool is purpose-built for head-to-head comparison across multiple cases.

How to Estimate Skin Values Per Tier

The accuracy of any EV comparison depends on the skin values you input. Here are practical approaches to getting reliable estimates:

• Steam Community Market: Check current median sale prices for all skins in a case at each rarity tier, then average them. This gives the most accurate market-based estimate.
• Third-party trackers: Sites like CSFloat aggregate market data and can help you find average values faster than manual lookups.
• Account for StatTrak: Roughly 10% of drops are StatTrak, which generally command a premium. You can weight your average accordingly — though for simplicity, this tool uses non-StatTrak averages by default.
• Include Knife/Glove values carefully: The Knife/Glove tier is extremely rare (0.26%) but high-value. Even small changes in the estimated Knife value significantly impact EV because of the wide range of possible Knife finishes.

For a deeper understanding of rarity tiers and their significance, our CS2 Skin Rarity Tiers Guide provides comprehensive coverage of every tier and color code.

Interpreting Your Results

After comparing cases, you will see several key metrics:

• Gross EV: The average value of items you receive per case opened, before subtracting costs.
• Net EV: Gross EV minus the case + key cost. This number will almost always be negative.
• ROI %: Net EV divided by cost, expressed as a percentage. A -20% ROI means you lose $0.20 for every $1.00 spent.
• Loss Per Case: How much money you lose on average per case opened. The lower (closer to zero), the better.

According to research on loot box economics published by the GambleAware Foundation, understanding expected loss is crucial for responsible participation. Even "better" cases still have negative expected value — this tool helps you see the relative differences clearly.