A free darts game with 501 and round the clock
Pub Darts in Games by Zaweba gives you a proper pub dartboard and a hand that won't keep still, with 501 and round the clock. Free and offline.

Pub Darts in Games by Zaweba is a free darts game for Windows with a proper pub dartboard, a hand that won't keep still and two ways to play: 501 and round the clock. It is part of a collection of 82 original games that work offline with no adverts and no account.
What makes it more than a click-on-the-treble game is the sway. Your aim drifts in a slow figure of eight, so every throw is about timing as much as aiming.
Throwing with a hand that sways
Watch the sight as it drifts across the board and click when it passes over the bed you want. That is the whole control, and it is enough to make a twenty feel earned. Hold Space to hold your breath and the sway calms down, which is the key to the harder targets. But you can't hold it for long, so the knack is to take the breath just as the sight is drifting towards your target, not before.
Players new to the game tend to chase the sight around the board. It works better to pick a spot, wait for the figure of eight to bring the sight through it, then use the held breath for the last moment of the approach.
Playing 501
In 501 you score down from 501 to exactly zero, and the last dart must land in a double or the bull. Go below 2 or miss the finishing double and it is a bust. Fewest darts wins. That means the game has two halves: heavy scoring early, then careful arithmetic and accurate doubles at the end.
While you are scoring, the treble twenty is the obvious target, but with a moving hand it is not always the best one. A safe big number in the single bed is often worth more over a visit than a treble you hit one time in four. As you get near the finish, think about which double you want to leave yourself. Even numbers that halve neatly are friendlier than odd ones, which need a single first.
Round the clock
Round the clock is the practice game, and a good one. Hit 1 to 20 in order, then the bull, in as few darts as you can. It forces you to aim at every part of the board rather than just the top, and it shows quickly which numbers your sway makes hard. Many people find the numbers at the sides trickier than the ones at the top and bottom.
Because the best score is kept per game and per mode, 501 and round the clock each keep their own record, so you can improve one without the other getting in the way.
Finding Pub Darts and getting comfortable
Pub Darts is on the Skill & sport shelf of Games by Zaweba, or press Ctrl+F and type darts to find it. The title card explains the rules and controls, and F1 brings them back during a game. Esc pauses whenever you need to, and F11 makes the board fill the screen, which makes the small doubles noticeably easier to see.
Your plays and best score are kept on the game's tile in a scores file on your own PC. The dartboard is drawn in code and every thud of a dart is made the same way, so the game needs no downloads and nothing goes online. If you like the sway, Bullseye Archery on the same shelf uses a very similar held breath, at a target fifty metres away.