Everything People Ask About the Playability Score

The home page has five FAQ items. People keep asking the same five and a half more. This is the long version — how the Playability Score is actually calculated, why the weights are what they are, and the situations where the score itself can mislead you.

Why is latency weighted at 30%, not 50%?

Latency is the single most important factor, so it carries the most weight. But it isn't the only thing that matters — a 20 ms ping with 50 ms of jitter is worse than a 50 ms ping with 2 ms of jitter, for actually playing Dota 2. If latency carried 50% on its own, jitter and packet loss could collapse and the score would still look fine. Spreading the weight across five metrics forces all of them to be reasonable before the score goes green.

Why does packet loss get 25%? That seems high.

Because packet loss is uniquely bad for real-time games. A dropped UDP packet for Dota 2 doesn't get retransmitted — it's just gone. The result is a missed input, a frozen frame, or a hero teleporting because the position update arrived late. Even 1% packet loss noticeably degrades a match. 3% is unplayable. So packet loss gets penalised more aggressively per unit than the others.

Why are download and upload bandwidth weighted at all? Dota 2 barely uses bandwidth.

Two reasons. First, very low bandwidth — under about 1 Mbps — does cause problems in practice, usually because the connection saturates at peak moments and starts dropping or buffering packets. Second, low uploadbandwidth is a warning sign on its own; it often correlates with congested last-mile equipment or oversubscribed CGNAT, both of which add jitter. The weights for bandwidth are deliberately small (15% download, 10% upload) — enough that a truly broken connection can't score 100, but not enough to penalise a fine 25 Mbps line just for not being a gigabit.

When does the score lie?

The score is a snapshot. Real connections are noisy. A 15-second test can miss a problem that only appears at specific times (8pm prime-time congestion), under specific loads (when your flatmate streams 4K), or due to specific routes (a peering hiccup that only kicks in for some destinations). Conversely, the test can flag a transient spike — a passing WiFi interference — as a permanent issue.

This is why the optional Stability Monitor exists. It pings every 15 seconds for as long as you leave it on, and feeds the variance back into a refined score. If you want a number you trust, run the diagnostic once for the baseline, then leave the monitor on while you watch a spectated match for 20 minutes.

The test gave me a great score but the game still lags. Why?

Three common reasons:

• Your route to the game server is different from your route to this site.The site's endpoints run on Vercel; Dota 2 servers run on Valve's infrastructure. The first half of the path is the same (your home, your ISP, the IXP), but the destinations differ. Most of the time the experience is similar; sometimes it isn't.
• The problem is intermittent and didn't hit during the test window. Run the test a few times at different moments, or use the Stability Monitor for a longer sample.
• The problem is not network at all. Frame drops can look like lag. If your GPU or CPU is the bottleneck, the network will look fine because it is fine — but the game still stutters. Check cl_showfps in console while playing.

What the score does NOT measure

• NAT type and port reachability. Symmetric NAT or CGNAT can cause connection issues unrelated to latency.
• UDP-specific behaviour.The browser tests use TCP-based HTTP requests. For 95% of connections this is a fine proxy. For the other 5% it isn't.
• Long-tail latency.The test reports averages and standard deviation. It doesn't tell you about p99 packet delays in detail.
• Anything Valve-side.If the SEA matchmaker itself is congested, the test won't catch it because it doesn't talk to Valve.

Is the score the same on phone and PC?

The test itself is identical. The result will differ because a phone on WiFi or 5G has different last-mile behaviour from a wired PC on the same connection. A phone score gives you a sense of "is the connection itself fine right now," but for the actual playing experience you want to test on the device you'll play on.

Where did the thresholds come from?

Public Valve developer docs on Source/Source 2 networking, community measurement threads on r/DotA2 and r/Philippines, and competitive-scene tolerances reported by professional players. The thresholds are tuned for Dota 2 specifically — they would be wrong for a turn-based game and they would be stricter for a 240 Hz first-person shooter. Full breakdown on the How It Works page.

Will the score change over time?

Yes. The weights can be adjusted as I learn more from community feedback and as Dota 2 patches change tick rates or netcode. When that happens it'll be documented on the How It Works page with the change date. The history feature in the tool stores raw values, not just the score, so old entries can be re-evaluated if needed.