[{"data":1,"prerenderedAt":421},["ShallowReactive",2],{"post-\u002Fblog\u002Fcomment-throw-compte-les-flechettes":3,"post-other-\u002Fblog\u002Fcomment-throw-compte-les-flechettes":219},{"id":4,"title":5,"body":6,"date":209,"description":210,"extension":211,"key":212,"meta":213,"navigation":214,"path":215,"seo":216,"stem":217,"__hash__":218},"blog_fr\u002Fblog\u002Fcomment-throw-compte-les-flechettes.md","Comment Throw compte tes fléchettes avec un seul téléphone",{"type":7,"value":8,"toc":197},"minimark",[9,13,18,26,37,40,44,55,62,66,73,77,80,83,87,98,102,105,121,124,128,131,157,164,168,171,194],[10,11,12],"p",{},"Tu poses ton téléphone à côté de la cible, tu lances, et le score s'affiche tout seul. Pas de caméras à fixer autour de la cible, pas de boîtier, pas de serveur. Voici, sans jargon, ce qui se passe entre le moment où ta fléchette se plante et celui où le score s'affiche.",[14,15,17],"h2",{"id":16},"étape-1-repérer-la-cible-une-seule-fois","Étape 1 : repérer la cible (une seule fois)",[10,19,20,21,25],{},"Avant de compter quoi que ce soit, Throw doit savoir ",[22,23,24],"strong",{},"où est la cible"," dans l'image, et sous quel angle il la voit. Filmée de côté, une cible ronde devient un ovale déformé : il faut pouvoir « redresser » l'image.",[10,27,28,29,32,33,36],{},"C'est le seul moment où l'intelligence artificielle intervient. Un petit modèle, qui tourne sur le téléphone, retrouve ",[22,30,31],{},"6 points de repère"," sur le bord extérieur de l'anneau des doubles. Avec ces 6 points, Throw calcule la correspondance entre chaque pixel de l'image et chaque millimètre de la cible. Il en profite pour ",[22,34,35],{},"mesurer les anneaux"," de ta cible (triple, double), parce que toutes les cibles ne sont pas exactement identiques au millimètre.",[10,38,39],{},"Cette calibration se fait au début, cible vide et calme. Si quelqu'un bouscule le téléphone en cours de partie, Throw le remarque et recalibre dès que la scène redevient calme.",[14,41,43],{"id":42},"étape-2-comparer-avant-et-après","Étape 2 : comparer avant et après",[10,45,46,47,50,51,54],{},"C'est le cœur du système, et il n'y a plus d'IA du tout. Throw garde en mémoire une image de la cible ",[22,48,49],{},"avant"," ta fléchette. Quand quelque chose bouge (ta fléchette qui arrive), il attend que tout se stabilise, une fraction de seconde le temps que l'empennage arrête de vibrer, puis il prend une image ",[22,52,53],{},"après",".",[10,56,57,58,61],{},"Il compare les deux. Les fléchettes déjà plantées sont dans les deux images, donc elles s'annulent. Ce qui reste, c'est ",[22,59,60],{},"la nouvelle fléchette",", et rien qu'elle. Avant la comparaison, Throw réaligne les deux images : la cible et le téléphone bougent toujours d'un ou deux pixels à chaque impact, et sans ce réalignement tout apparaîtrait comme « changé ».",[14,63,65],{"id":64},"étape-3-trouver-la-pointe","Étape 3 : trouver la pointe",[10,67,68,69,72],{},"Repérer la fléchette ne suffit pas : ce qui compte, c'est l'endroit où ",[22,70,71],{},"la pointe"," entre dans la cible. Or une pointe acier fait 2 mm de large, elle est presque invisible. Throw la retrouve par géométrie : il repère la forme de la fléchette, en déduit son axe, puis suit cet axe jusqu'à l'endroit où la fléchette entre dans la cible.",[14,74,76],{"id":75},"étape-4-compter-les-points","Étape 4 : compter les points",[10,78,79],{},"Une fois la pointe placée, il n'y a plus qu'à la reporter sur la cible « redressée » : à quelle distance du centre (simple, triple, double, bull ?) et dans quel secteur (le 20, le 1, le 18...). C'est du calcul pur, toujours le même résultat pour la même position.",[10,81,82],{},"Quand tu retires tes fléchettes, Throw voit qu'elles ont disparu et valide la volée. C'est au joueur suivant.",[14,84,86],{"id":85},"tout-se-passe-sur-ton-téléphone","Tout se passe sur ton téléphone",[10,88,89,90,93,94,97],{},"Aucune image n'a besoin de partir sur un serveur pour être analysée : tout le calcul tourne ",[22,91,92],{},"sur le téléphone",". Throw est une application web que tu installes depuis ton navigateur, sans passer par un store, sur iPhone comme sur Android. Le modèle de calibration se télécharge une fois au premier lancement de la caméra, ensuite l'app ",[22,95,96],{},"fonctionne hors ligne",", au fond d'une cave comme au bar.",[14,99,101],{"id":100},"ce-que-ça-donne","Ce que ça donne",[10,103,104],{},"Pour tester honnêtement, on a filmé de vraies sessions de jeu, téléphone sur le côté, avec à côté un système Autodarts à trois caméras qui servait d'arbitre. Sur ces sessions (144 fléchettes) :",[106,107,108,115],"ul",{},[109,110,111,114],"li",{},[22,112,113],{},"98 %"," des fléchettes sont repérées ;",[109,116,117,120],{},[22,118,119],{},"à peu près 9 fléchettes sur 10"," tombent dans le même secteur que celui donné par Autodarts. Et l'arbitre se trompe parfois aussi : en vérifiant les désaccords à l'image, quelques-uns sont de sa faute.",[10,122,123],{},"Pour comparaison, notre première approche, qui cherchait les fléchettes dans une seule photo en fin de volée, plafonnait à 57 % sur les mêmes images.",[14,125,127],{"id":126},"les-limites-en-toute-franchise","Les limites, en toute franchise",[10,129,130],{},"Une seule caméra, c'est un seul point de vue. Certaines situations restent difficiles :",[106,132,133,139,145,151],{},[109,134,135,138],{},[22,136,137],{},"Le rebond"," : une fléchette qui ressort de la cible ne laisse rien à voir. Tu la marques « Rebond » d'un tap.",[109,140,141,144],{},[22,142,143],{},"La fléchette cachée"," : si l'empennage d'une fléchette déjà plantée masque la nouvelle, la caméra ne peut pas inventer ce qu'elle ne voit pas.",[109,146,147,150],{},[22,148,149],{},"Sur le fil"," : à un ou deux millimètres près, le verdict peut tomber du mauvais côté.",[109,152,153,156],{},[22,154,155],{},"La pointe claire sur case claire"," : parfois, elle ne se distingue presque pas.",[10,158,159,160,163],{},"Dans tous ces cas, la correction est faite pour être rapide : un ",[22,161,162],{},"tap sur la case"," de la fléchette, tu choisis la bonne valeur, et le score se recalcule.",[14,165,167],{"id":166},"et-maintenant-en-ligne-et-sur-grand-écran","Et maintenant : en ligne et sur grand écran",[10,169,170],{},"Deux nouveautés sont arrivées :",[106,172,173,179],{},[109,174,175,178],{},[22,176,177],{},"Jouer en ligne"," contre tes amis, en un contre un, chacun devant sa cible avec son téléphone. Pas de vidéo : ton adversaire voit une image de ta cible à chaque fléchette, et chaque correction s'affiche chez lui. Il faut un compte (gratuit), pas pour regarder une partie publique.",[109,180,181,184,185,189,190,193],{},[22,182,183],{},"Un écran pour le salon ou le bar"," : ouvre ",[186,187,188],"code",{},"throw.maz-ui.com\u002Fapp\u002Fscreen"," sur un PC ou une TV, puis sur le téléphone, dans le menu de la partie, touche ",[22,191,192],{},"Écran"," et tape le code affiché. La partie que ton téléphone compte s'affiche en grand, sans compte.",[10,195,196],{},"Le téléphone garde tout : tous les jeux restent jouables seul et hors ligne, le compte et le mode en ligne viennent en plus, jamais en obligation.",{"title":198,"searchDepth":199,"depth":199,"links":200},"",2,[201,202,203,204,205,206,207,208],{"id":16,"depth":199,"text":17},{"id":42,"depth":199,"text":43},{"id":64,"depth":199,"text":65},{"id":75,"depth":199,"text":76},{"id":85,"depth":199,"text":86},{"id":100,"depth":199,"text":101},{"id":126,"depth":199,"text":127},{"id":166,"depth":199,"text":167},"2026-10-26","Un téléphone posé à côté de la cible, et le score se compte tout seul. Calibration, image avant et après, pointe trouvée par géométrie : on t'explique tout.","md","how-throw-scores",{},true,"\u002Fblog\u002Fcomment-throw-compte-les-flechettes",{"title":5,"description":210},"blog\u002Fcomment-throw-compte-les-flechettes","0MeNs-91aAono1fG-eb9ZGoKjUVQaKqk7TjIocvpwNs",{"id":220,"title":221,"body":222,"date":209,"description":415,"extension":211,"key":212,"meta":416,"navigation":214,"path":417,"seo":418,"stem":419,"__hash__":420},"blog_en\u002Fen\u002Fblog\u002Fhow-throw-scores-your-darts.md","How Throw scores your darts with a single phone",{"type":7,"value":223,"toc":405},[224,227,231,238,249,252,256,267,274,278,285,289,292,295,299,310,314,317,331,334,338,341,367,374,378,381,402],[10,225,226],{},"You stand your phone beside the board, you throw, and the score appears on its own. No cameras bolted around the board, no extra hardware, no server. Here's what happens, in plain terms, between your dart landing and the score showing up.",[14,228,230],{"id":229},"step-1-find-the-board-once","Step 1: find the board (once)",[10,232,233,234,237],{},"Before it can score anything, Throw has to know ",[22,235,236],{},"where the board is"," in the picture and what angle it's seeing it from. Filmed from the side, a round board turns into a squashed oval, and the image needs to be \"straightened out\".",[10,239,240,241,244,245,248],{},"This is the only step that uses artificial intelligence. A small model, running on the phone, finds ",[22,242,243],{},"6 reference points"," on the outer edge of the double ring. From those 6 points Throw works out how every pixel in the image maps to every millimetre of the board. It also ",[22,246,247],{},"measures the rings"," on your actual board (treble, double), because not every board is identical to the millimetre.",[10,250,251],{},"Calibration happens at the start, with the board empty and still. If someone knocks the phone mid-game, Throw notices and recalibrates as soon as things settle down.",[14,253,255],{"id":254},"step-2-compare-before-and-after","Step 2: compare before and after",[10,257,258,259,262,263,266],{},"This is the heart of the system, and there's no AI involved at all. Throw keeps an image of the board from ",[22,260,261],{},"before"," your dart. When something moves (your dart arriving), it waits for everything to settle, a fraction of a second while the flight stops wobbling, then takes an ",[22,264,265],{},"after"," image.",[10,268,269,270,273],{},"It compares the two. Darts already in the board appear in both images, so they cancel out. What's left is ",[22,271,272],{},"the new dart",", and only that. Before comparing, Throw lines the two images back up: the board and the phone always shift by a pixel or two on each impact, and without that step everything would look \"changed\".",[14,275,277],{"id":276},"step-3-find-the-tip","Step 3: find the tip",[10,279,280,281,284],{},"Spotting the dart isn't enough. What matters is where ",[22,282,283],{},"the tip"," goes into the board, and a steel tip is about 2 mm wide, close to invisible. Throw finds it with geometry: it picks out the shape of the dart, works out its axis, then follows that axis to the point where the dart enters the board.",[14,286,288],{"id":287},"step-4-score-it","Step 4: score it",[10,290,291],{},"Once the tip is placed, it just has to be dropped onto the straightened board: how far from the centre (single, treble, double, bull?) and which segment (20, 1, 18...). It's pure calculation, the same position always gives the same result.",[10,293,294],{},"When you pull your darts out, Throw sees they're gone and confirms the visit. Next player.",[14,296,298],{"id":297},"it-all-runs-on-your-phone","It all runs on your phone",[10,300,301,302,305,306,309],{},"No image has to go to a server to be analysed: all the work happens ",[22,303,304],{},"on the phone",". Throw is a web app you install straight from your browser, no app store needed, on iPhone and Android alike. The calibration model downloads once, the first time you start the camera, and after that the app ",[22,307,308],{},"works offline",", in the garage or down the pub.",[14,311,313],{"id":312},"how-well-does-it-work","How well does it work?",[10,315,316],{},"To test it honestly, we filmed real play sessions with the phone off to the side, next to an Autodarts setup with three cameras acting as referee. Over those sessions (144 darts):",[106,318,319,325],{},[109,320,321,324],{},[22,322,323],{},"98%"," of darts were picked up;",[109,326,327,330],{},[22,328,329],{},"roughly 9 darts out of 10"," landed in the same segment Autodarts gave. And the referee gets it wrong now and then too: checking the disagreements frame by frame, a few were on Autodarts' side.",[10,332,333],{},"For comparison, our first approach, which looked for the darts in a single photo at the end of the visit, topped out at 57% on the same footage.",[14,335,337],{"id":336},"the-limits-honestly","The limits, honestly",[10,339,340],{},"One camera means one point of view, and some situations stay tricky:",[106,342,343,349,355,361],{},[109,344,345,348],{},[22,346,347],{},"Bounce-outs",": a dart that falls out of the board leaves nothing to see. Tag it as a bounce with a tap.",[109,350,351,354],{},[22,352,353],{},"Hidden darts",": if the flight of a dart already in the board hides the new one, the camera can't make up what it can't see.",[109,356,357,360],{},[22,358,359],{},"On the wire",": within a millimetre or two, the call can go the wrong way.",[109,362,363,366],{},[22,364,365],{},"A light tip on a light bed",": sometimes it barely shows up at all.",[10,368,369,370,373],{},"In every one of these cases, fixing it is meant to be quick: ",[22,371,372],{},"tap the dart's slot",", pick the right value, and the score is recalculated.",[14,375,377],{"id":376},"now-online-and-on-the-big-screen","Now: online and on the big screen",[10,379,380],{},"Two new things are here:",[106,382,383,389],{},[109,384,385,388],{},[22,386,387],{},"Online play"," against your friends, one on one, each of you at your own board with your own phone. No video: your opponent sees an image of your board with every dart, and every correction shows on their side. You need a (free) account to play, not to watch a public game.",[109,390,391,394,395,397,398,401],{},[22,392,393],{},"A screen for the living room or the bar",": open ",[186,396,188],{}," on a computer or a TV, then on the phone, in the game menu, tap ",[22,399,400],{},"Screen"," and type the code shown. The game your phone is scoring appears on the big screen, no account needed.",[10,403,404],{},"The phone keeps everything: every game stays playable on your own and offline, accounts and online play come on top, never as a requirement.",{"title":198,"searchDepth":199,"depth":199,"links":406},[407,408,409,410,411,412,413,414],{"id":229,"depth":199,"text":230},{"id":254,"depth":199,"text":255},{"id":276,"depth":199,"text":277},{"id":287,"depth":199,"text":288},{"id":297,"depth":199,"text":298},{"id":312,"depth":199,"text":313},{"id":336,"depth":199,"text":337},{"id":376,"depth":199,"text":377},"One phone beside the board and the score keeps itself. Calibration, before and after images, a tip found by geometry: here's how Throw scores your darts.",{},"\u002Fen\u002Fblog\u002Fhow-throw-scores-your-darts",{"title":221,"description":415},"en\u002Fblog\u002Fhow-throw-scores-your-darts","oQZHV_wUcbnFzJ4eHqsj4u5huTUCO1E_IeOD-gGGjtA",1794595396304]