Chart a Team's Scoring-Margin Trend Over a Season (Python)

A season is a story, and the simplest way to see its arc is to plot a team's scoring margin game by game. Blowouts, nail-biters, the bad loss, the turnaround — they all jump out of a single bar chart. This is the gentlest possible data-viz tutorial, and a perfect first project. Full code: scripts/cfb-scoring-margin-trend-python.py.

Get one team's games in order

Using the shared season helper (ESPN results), filter to the games involving your team and compute the margin from that team's perspective:

from _cfb_season import season_games
games = sorted(season_games(2024), key=lambda g: g["week"])
log = []
for g in games:
    if g["home"] == "OSU":
        log.append((g["week"], g["away"], g["hs"] - g["as"]))
    elif g["away"] == "OSU":
        log.append((g["week"], g["home"], g["as"] - g["hs"]))   # flip sign on the road

Plot it

Color the bars by win (navy) or loss (brick), and add a line for the season average:

ys = [m for _, _, m in log]
colors = ["#14213d" if m >= 0 else "#9b3a2c" for m in ys]
ax.bar(range(len(ys)), ys, color=colors)
ax.axhline(sum(ys)/len(ys), ls="--")     # season average margin

The result

Ohio State 2024 game-by-game margin:
  Wk 1 vs AKR  +46     Wk 7 vs ORE   -1
  Wk 2 vs WMU  +56     Wk 9 vs NEB   +4
  Wk 4 vs MRSH +35     Wk10 vs PSU   +7
  Wk 5 vs MSU  +31     Wk11 vs PUR  +45
  Wk 6 vs IOWA +28     Wk12 vs NU   +24
                       Wk13 vs IU   +23
                       Wk14 vs MICH  -3
Average margin: +24.6

The chart tells the season's story at a glance: a +24.6 average margin built on early blowouts, then the two losses that nearly ended the playoff dream — a one-point heartbreaker to Oregon and a three-point stunner to Michigan in the finale. What it can't show is the twist: this team then won four straight playoff games to win the national title. A margin chart captures the regular-season arc beautifully — and reminds you why we don't crown champions by average margin alone (see the Elo tutorial, where this same Ohio State ranks only 12th).

Variations

• Rolling average. Add a 3-game moving line to smooth the noise and reveal momentum.
• Cap the bars at ±28 to keep one 56-point blowout from dominating the axis.
• Overlay opponent quality by coloring bars by the opponent's rank — a tough loss looks different from a bad one.