diff --git a/exploring-curve-shapes.rkt b/exploring-curve-shapes.rkt
new file mode 100644
index 0000000..e000099
--- /dev/null
+++ b/exploring-curve-shapes.rkt
@@ -0,0 +1,23 @@
+#lang racket
+;; Experiment with different hypotheses about data curves.
+(require plot)
+
+(define k 0.00035) ;; seconds
+(define a 0.00007) ;; seconds
+(define gc-time-per-n 0.0000002)
+
+;; It's quite possible that the curve I'm seeing is logarithmic in the
+;; group size for the actual work, plus some GC overhead linear in the
+;; group size.
+(define (RTT n)
+  (+ ;; Work:
+     (+ k (* a (/ (log n) (log 2.718))))
+     ;; GC overhead?:
+     (* n gc-time-per-n)))
+
+(parameterize ((plot-x-transform log-transform)
+               (plot-x-ticks (log-ticks)))
+  (plot-pict (function RTT 1 1076 #:label "RTT")
+             #:height 450
+             #:width 700
+             #:y-min 0))