```python
def versions_behind(mod: Mod) -> int:
    try:
        all = game_versions(mod.game)
        compat = version.Version(mod.default_version.gameversion.friendly_version)
        return sum(1 for v in all if v > compat)
    except:
        return 0

def game_versions(game: Game) -> Iterable[version.Version]:
    for gv in game.versions:
        try:
            ver = version.Version(gv.friendly_version)
            yield ver
        except:
            pass
```

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