Read your spray chart

A spray chart is one dot per at-bat that had a location tapped on the field while it was being recorded, drawn on that same field. Nothing else puts a dot there, so an at-bat with no location is on no chart at all — which is why a game typed in from a box score is in every number you have and in none of the pictures.

A dot's colour is the outcome of that at-bat and nothing else — not how hard it was hit, not when, not who was pitching. Green is a single, blue a double, purple a triple, gold a home run, red an out, and cyan a fielder's choice or reaching on an error. Each dot also carries its own short code in the middle of it — 1B, 2B, 3B, HR, GO, FO and so on — so the colour and the word always agree, and the legend along the top of the chart on the website and under it on the phone is drawn from exactly those six colours rather than from a list somebody typed, which is what keeps it honest in dark mode. The only extra mark is a faint ring around a home run: emphasis on the dot everybody looks for, not a seventh colour.

The chart opens showing your hits, not everything, so the first thing worth doing is deciding which slice you are looking at. All is every ball that was put in play. Outs is the ones you were retired on, counting a sacrifice fly or a sacrifice bunt as an out because the fielder caught it — even though neither dents your average. A fielder's choice and reaching on an error are in neither Hits nor Outs, because the batter reached base without a hit; the only way to see those two cyan dots is All.

Zones splits the field into four, and the four are the infield, left field, centre field and right field. The infield is the diamond itself — the quadrilateral between home, first, second and third — and it is tested first, so a ball that landed between the bases is infield whichever side it was on. Everything outside the diamond is sorted by the angle it left home plate at, into three equal thirds of fair territory: left field from the foul line to a third of the way across, centre field the middle third, right field the rest. That means depth decides only one thing, infield or not; a blooper that dropped just behind the shortstop is in left field, the same as one off the fence.

Each wedge carries three lines — AVG, then SLG, then the number of balls hit there. The green shading is volume and only volume: the zone you hit to most is the darkest, and a zone with nothing in it is not shaded at all. It is deliberately not tinted by average, because then a single ball you happened to hit for a double would be the brightest thing on the field.

The one number on that overlay people mistrust is the AVG, and it is right — it is just not the average they are comparing it against. Only a ball in play has a location, so a zone's AVG is worked out over the at-bats that ended with a ball hit there and nothing else: every strikeout you have is in no zone, which is most of the gap. A zone with balls in it but no official at-bats — all sacrifices, say — prints an em dash rather than .000, because nought-for-nought is not a zero. And at-bats with no location are counted in their own line under the chart instead of being dropped, since every rate above that line is worked out as though they never happened.

Your chart is not the only one. The game's own page draws just that game's at-bats, a team's page draws the whole roster's, and a card you share carries a chart of its own — drawn from the same locations, but deliberately not coloured like this one.

Everything above obeys whatever the stats filters are set to, on both apps, so "my spray chart" is really "my spray chart for this slice" — one season, one opponent, one field, or the lot.