PINBALL - credits, sources and corrections ========================================== WHAT THIS IS ------------ An independent reimplementation of the PUBLISHED PHYSICS AND CONVENTIONS of a pinball machine, written from scratch for the browser. "Pinball" is the name of the game itself - a category, not a machine and not a trademark of this app. WHAT IS NOT HERE ---------------- No commercial pinball machine is reproduced. No manufacturer's playfield layout, artwork, rule set, mode names, sound or trade dress appears in this app, and none was used as a reference. The table below is this app's own design; so are the shot names, the scoring and every colour on the screen. What IS reproduced is the machine's grammar - a shooter lane, top rollover lanes, a pop bumper nest, slingshots, two flippers over a drain with an inlane and an outlane either side, a ramp to a raised deck, a drop-target bank, and a plumb-bob tilt - because that grammar is the sport, and it is documented in encyclopaedias, rulebooks and service literature, not owned. ORIGINAL, AUTHOR, YEAR ---------------------- Pinball has no single author. The element this app is really built around - the player-controlled flipper - was introduced by Gottlieb in "Humpty Dumpty" in 1947, designed by Harry Mabs. The two-flipper-above-the-drain arrangement this table uses became standard in the early 1950s. Source: Wikipedia, "Pinball" - https://en.wikipedia.org/wiki/Pinball SOURCES ACTUALLY OPENED ----------------------- Every document below was fetched and read during this build. Nothing is quoted that could not be opened; where something could not be opened, that is said so explicitly further down. 1. PAPA/IFPA unified competition rules (PDF, 16 pages), linked from the PAPA 23 rules page and described there as the controlling rule set maintained jointly by IFPA and Replay Foundation. https://lfs.papa.org/papa23/PAPA_IFPA-Complete-Competition-Rules-2023.09.pdf Used for: three balls; two tilt warnings; extra balls disabled; a tilt costs the current ball; slam tilt scores zero; the stuck-ball and ball-search procedure. Quoted: "3 Balls"; "2 Tilt Warnings (may be 0 on older machines)"; "Extra Balls disabled"; "Any player who tilts his or her ball in play will not receive any penalty other than the normal loss of ball"; "If the stuck ball has not been freed after four such searches ... the player must alert the scorekeeper". 2. PAPA 23 Official Rules (event page). https://lfs.papa.org/papa23/rules.php Used for: the 30-second intentional-delay limit and the same machine-settings list. 3. Wikipedia, "Pinball". https://en.wikipedia.org/wiki/Pinball Quoted: "The playfield is a planar surface inclined upward, usually at six and a half degrees"; the pop bumper mechanism ("a switch connected to a ring surrounding the bottom circumference of the bumper ... activates the bumper's solenoid ... pushes downward and outward on the ball"); the two-winding flipper coil and its end-of-stroke switch; the three kinds of tilt sensor. 4. Williams' own "Ask Uncle Willy" column, issue 14, 29 July 1997. https://www.planetarypinball.com/mm5/Williams/archives/willy14.htm Quoted: "Why is 6.5 degree the preferred playfield angle? Did it used to be 3 degrees?" and the answer, which also says plainly that the origin of the precise 6.5 figure is folklore. 5. PinWiki, "General", sections "Adjusting the Game Pitch" and "Tweaking Tilt Mechanisms". https://www.pinwiki.com/wiki/index.php?title=General Quoted: "the 'Rule of Thumb' is 3 1/2 degrees for EM games and 6 1/2 to 7 degrees for solid state games"; "the position you put the plumb bob in makes a huge difference in how the tilt operates ... The inverted position allows quicker recovery after a tilt"; "may in fact swing for a very long time (2 minutes or more depending on the force imparted)". 6. Wikipedia, "Glossary of pinball terms". https://en.wikipedia.org/wiki/Glossary_of_pinball_terms Used for: outlane, inlane, slingshot, kickback, skill shot, ball save, nudge, ramp. 7. German Wikipedia, "Flipperautomat". https://de.wikipedia.org/wiki/Flipperautomat Quoted: "Ungefaehr Anfang der 1970er Jahre setzten sich laengere Flipperhebel (3 Zoll (7,62 cm) statt 2 Zoll (5,08 cm)) durch." 8. A parts distributor's catalogue listing for the standard ball, Williams part 20-6500, sold as "Budget Pinball Standard 20-6500 steel 1-1/16". https://www.pinballspareparts.com.au/20-6500-b.html and the flipper bat listings, which carry both the 3" and the 2" bats as separate parts: https://www.pinballspareparts.com.au/catalogsearch/result/?q=flipper+bat CORRECTIONS - things one might expect to find in these sources, that are not there ---------------------------------------------------------------------------------- These are recorded because getting them wrong would have meant three fabricated citations. A. https://www.ifpapinball.com/rules/ COULD NOT BE OPENED. It sits behind a Cloudflare interstitial and returns 403 to every non-browser client. Nothing in this app cites it. The IFPA rules text used here came from the unified PAPA/IFPA PDF above, which IFPA co-publishes. B. THE PAPA "LEARNING CENTER" NO LONGER EXISTS. papa.org has no HTTPS listener of its own and 301s to https://lfs.papa.org/papa23/. The learning-centre video series is not reachable at that address. Nothing here cites it. C. THE COMPETITION RULES STATE NO PLAYFIELD PITCH. The hardware-settings section of the unified rules reads, in full: "Each machine will be properly leveled left-to-right and inclined front-to-back." The words "degree", "pitch" and "angle" do not appear anywhere in the document. The 6.5 degree figure is a manufacturer and encyclopaedia convention, not a competition rule, and this app says so on the page. D. THE RULES DO NOT DEFINE A BALL SAVE. "Ball save" appears only as an example of a BENEFICIAL MALFUNCTION - "an unexpected software ball save" - allowed once per game. Ball savers themselves are left at "Standard Factory Settings". The 7-second saver in this app is this app's own choice and is labelled as such. E. THERE IS NO RULE DEFINING A LEGAL PLUNGE. The rules only say autolaunch is disabled for tournament play and that a ball left sitting in the plunger lane counts as an intentional delay. F. THE ENCYCLOPAEDIAS DISAGREE ABOUT FLIPPER LENGTH. English Wikipedia gives "roughly 3 to 7 cm (1+1/4 to 2+3/4 in)"; German Wikipedia gives 3 inch (7.62 cm) replacing 2 inch (5.08 cm) in the early 1970s. Both lengths are sold as distinct parts today. This app uses 76.2 mm, the length a part is actually sold by, and records the disagreement here. WHAT IS SOURCED, WHAT IS DERIVED, WHAT IS CALIBRATED ---------------------------------------------------- SOURCED ball diameter 1-1/16 in; playfield pitch 6.5 deg (and 3 to 3.5 deg for older games); flipper bat 3 in; three balls; two tilt warnings; extra balls off; tilt costs the ball; the pop bumper's position-switch-plus-solenoid mechanism; the two-winding flipper coil with an end-of-stroke switch; the plumb-bob-through-a-ring tilt and the effect of moving the bob along the rod; four ball searches before a stuck ball is dealt with by hand. DERIVED ball mass 80.79 g - that diameter times the density of carbon steel (7850 kg/m^3). It is NOT a citation; the density is a declared assumption. The commonly quoted "about 80 g" agrees with the derivation, which is why no citation was hunted for a computable number. CALIBRATED (this app's own numbers; no manufacturer publishes them) kinetic and rolling friction, wall and rubber restitution, the pop and slingshot coil impulses, the flipper's moment of inertia and coil torques, the plunger spring rate, the tilt bob's masses and lengths and the restitution of its strike against the ring, the rail groove angle, and every score. THIS APP'S OWN the table layout, the shot names, the scoring, the colours, the camera, the ball-search behaviour past the fourth search, and the decision to ship no one-way gate on the shooter lane. AN UNRESOLVED DIFFERENCE, STATED -------------------------------- PinWiki says a plumb bob in the normal position "may in fact swing for a very long time (2 minutes or more)". A bob that stayed in CONTACT WITH THE RING for two minutes would hand out hundreds of tilt warnings from one nudge, which no machine does. This app reconciles the two by putting most of the loss in the STRIKE against the ring (a restitution) and almost none in the wire: a big swing dies in three or four contacts, while a swing too small to reach the ring rings on for minutes. That reconciliation is this app's reasoning, not a published finding, and it is in the limits list on the page. HOW IT WAS CHECKED ------------------ Two oracles that cover each other's blind spots, plus a set of controls that are wrong by construction and must fail: * An EVENT-DRIVEN ANALYTIC SOLVER - closed-form contact times, a Ferrari quartic solver for circles under acceleration - checked against the fixed-step integrator. Shares no code and no method with it. * THE PITCH RECOVERED FROM AN EMITTED BALL TRACK, using nothing but positions and times and the fact that a uniform sphere rolls at 5/7 g sin(pitch). The engine never writes 5/7 down. * Energy accounting while rolling, which is blind to the coils and to the ball's inertia, so the track oracle is there to see the inertia and the speed-independence test is there to see the coils. * Controls: a passive-restitution bumper (fails the speed-independence claim), a point-mass ball (makes the track report 9.12 degrees for a 6.5 degree table), an input frozen across the four Runge-Kutta stages (collapses the scheme from fourth order to first), a flipper replaced by a fixed-speed paddle (loses the tip-versus-base variation entirely), a reversed polygon winding (fails the outward-normal test), and a flipped contact lever arm (breaks the no-slip condition and drifts the energy). The harness counts are in the deploy ledger. Anything it could not prove is in the limits list on the page, not hidden here.