PROBABILITY LAB

Trading ExpectancyPath Simulator

One set of assumptions. Twenty independent paths. See how the order of wins and losses can reshape the experience of the same theoretical expectancy.

This is a simplified educational model. It generates possible paths from the numbers you enter; it does not test a strategy or predict the future.

Model assumption: Each trade is independent, and the win rate, average win, and average loss remain fixed throughout the sample.

Follow One Path, Then Compare Twenty

45% win rate · 1.5R average win · 1R average loss · 200 trades

ONE REALIZED PATH

How Path 1 Unfolds

Follow one of the same 20 paths shown in the chart below, trade by trade.

Starting Index100

Ending Index150

Net Change+50R

The path index starts at 100. For this display, 1R equals 1 index point. This is not an account balance or percentage return.

Every trade in Path 1, showing its outcome, R change, and indexed path value starting from 100.
Trade	Outcome	Change	Path Index
0	Start	—	100
1	Win	+1.5R	101.5
2	Win	+1.5R	103
3	Win	+1.5R	104.5
4	Loss	-1R	103.5
5	Win	+1.5R	105
6	Loss	-1R	104
7	Win	+1.5R	105.5
8	Loss	-1R	104.5
9	Loss	-1R	103.5
10	Win	+1.5R	105
11	Loss	-1R	104
12	Win	+1.5R	105.5
13	Win	+1.5R	107
14	Win	+1.5R	108.5
15	Win	+1.5R	110
16	Loss	-1R	109
17	Loss	-1R	108
18	Win	+1.5R	109.5
19	Win	+1.5R	111
20	Win	+1.5R	112.5
21	Win	+1.5R	114
22	Loss	-1R	113
23	Loss	-1R	112
24	Win	+1.5R	113.5
25	Loss	-1R	112.5
26	Loss	-1R	111.5
27	Loss	-1R	110.5
28	Win	+1.5R	112
29	Win	+1.5R	113.5
30	Loss	-1R	112.5
31	Win	+1.5R	114
32	Loss	-1R	113
33	Win	+1.5R	114.5
34	Loss	-1R	113.5
35	Loss	-1R	112.5
36	Loss	-1R	111.5
37	Win	+1.5R	113
38	Win	+1.5R	114.5
39	Loss	-1R	113.5
40	Win	+1.5R	115
41	Win	+1.5R	116.5
42	Loss	-1R	115.5
43	Win	+1.5R	117
44	Loss	-1R	116
45	Win	+1.5R	117.5
46	Loss	-1R	116.5
47	Loss	-1R	115.5
48	Loss	-1R	114.5
49	Win	+1.5R	116
50	Loss	-1R	115
51	Loss	-1R	114
52	Win	+1.5R	115.5
53	Loss	-1R	114.5
54	Loss	-1R	113.5
55	Loss	-1R	112.5
56	Win	+1.5R	114
57	Win	+1.5R	115.5
58	Loss	-1R	114.5
59	Loss	-1R	113.5
60	Loss	-1R	112.5
61	Loss	-1R	111.5
62	Win	+1.5R	113
63	Loss	-1R	112
64	Win	+1.5R	113.5
65	Loss	-1R	112.5
66	Loss	-1R	111.5
67	Loss	-1R	110.5
68	Win	+1.5R	112
69	Win	+1.5R	113.5
70	Win	+1.5R	115
71	Loss	-1R	114
72	Win	+1.5R	115.5
73	Loss	-1R	114.5
74	Win	+1.5R	116
75	Win	+1.5R	117.5
76	Win	+1.5R	119
77	Loss	-1R	118
78	Win	+1.5R	119.5
79	Loss	-1R	118.5
80	Loss	-1R	117.5
81	Loss	-1R	116.5
82	Win	+1.5R	118
83	Win	+1.5R	119.5
84	Win	+1.5R	121
85	Loss	-1R	120
86	Win	+1.5R	121.5
87	Loss	-1R	120.5
88	Loss	-1R	119.5
89	Loss	-1R	118.5
90	Win	+1.5R	120
91	Loss	-1R	119
92	Win	+1.5R	120.5
93	Win	+1.5R	122
94	Win	+1.5R	123.5
95	Loss	-1R	122.5
96	Win	+1.5R	124
97	Loss	-1R	123
98	Win	+1.5R	124.5
99	Win	+1.5R	126
100	Win	+1.5R	127.5
101	Loss	-1R	126.5
102	Loss	-1R	125.5
103	Loss	-1R	124.5
104	Loss	-1R	123.5
105	Loss	-1R	122.5
106	Loss	-1R	121.5
107	Win	+1.5R	123
108	Win	+1.5R	124.5
109	Win	+1.5R	126
110	Loss	-1R	125
111	Loss	-1R	124
112	Loss	-1R	123
113	Win	+1.5R	124.5
114	Loss	-1R	123.5
115	Loss	-1R	122.5
116	Win	+1.5R	124
117	Loss	-1R	123
118	Win	+1.5R	124.5
119	Loss	-1R	123.5
120	Loss	-1R	122.5
121	Win	+1.5R	124
122	Win	+1.5R	125.5
123	Win	+1.5R	127
124	Loss	-1R	126
125	Loss	-1R	125
126	Win	+1.5R	126.5
127	Loss	-1R	125.5
128	Win	+1.5R	127
129	Win	+1.5R	128.5
130	Loss	-1R	127.5
131	Win	+1.5R	129
132	Loss	-1R	128
133	Loss	-1R	127
134	Win	+1.5R	128.5
135	Win	+1.5R	130
136	Loss	-1R	129
137	Loss	-1R	128
138	Win	+1.5R	129.5
139	Win	+1.5R	131
140	Win	+1.5R	132.5
141	Win	+1.5R	134
142	Win	+1.5R	135.5
143	Loss	-1R	134.5
144	Loss	-1R	133.5
145	Win	+1.5R	135
146	Win	+1.5R	136.5
147	Loss	-1R	135.5
148	Win	+1.5R	137
149	Loss	-1R	136
150	Loss	-1R	135
151	Loss	-1R	134
152	Loss	-1R	133
153	Loss	-1R	132
154	Loss	-1R	131
155	Win	+1.5R	132.5
156	Loss	-1R	131.5
157	Loss	-1R	130.5
158	Loss	-1R	129.5
159	Win	+1.5R	131
160	Loss	-1R	130
161	Win	+1.5R	131.5
162	Loss	-1R	130.5
163	Win	+1.5R	132
164	Loss	-1R	131
165	Loss	-1R	130
166	Loss	-1R	129
167	Win	+1.5R	130.5
168	Win	+1.5R	132
169	Win	+1.5R	133.5
170	Loss	-1R	132.5
171	Win	+1.5R	134
172	Win	+1.5R	135.5
173	Win	+1.5R	137
174	Win	+1.5R	138.5
175	Win	+1.5R	140
176	Win	+1.5R	141.5
177	Loss	-1R	140.5
178	Loss	-1R	139.5
179	Win	+1.5R	141
180	Loss	-1R	140
181	Loss	-1R	139
182	Win	+1.5R	140.5
183	Win	+1.5R	142
184	Loss	-1R	141
185	Loss	-1R	140
186	Win	+1.5R	141.5
187	Win	+1.5R	143
188	Win	+1.5R	144.5
189	Loss	-1R	143.5
190	Win	+1.5R	145
191	Loss	-1R	144
192	Win	+1.5R	145.5
193	Loss	-1R	144.5
194	Loss	-1R	143.5
195	Win	+1.5R	145
196	Win	+1.5R	146.5
197	Win	+1.5R	148
198	Loss	-1R	147
199	Win	+1.5R	148.5
200	Win	+1.5R	150

BATCH SUMMARY

What Happened Across All 20 Paths

The assumptions are identical. The realized number and order of wins and losses can differ from path to path.

Theoretical Expectancy per Trade

+0.125RBased on the assumptions above

Theoretical Total over 200 Trades

+25RExpectancy × number of trades

Median Final Cumulative R

+27.5RMiddle of the 20 realized endpoints

Final Cumulative R Range

-2.5R to +55R

Maximum Drawdown Range

7R to 26.5R

Longest Losing Streak Range

6 to 13 trades

Paths Finishing Below 0R

1 of 20

PATH VIEW

Twenty Realized Paths

Point to preview a path. Click or tap to keep it in focus. Drag across the chart to inspect any trade.

InspectionMove or drag across the chartClick or tap a path—on the chart or in the table—to keep it in focus.

PATH DETAILS

All 20 Paths

Select a path number to focus its line in the chart.

Final cumulative R, maximum drawdown, and longest losing streak for all 20 paths.
Final Cumulative R	Maximum Drawdown	Longest Losing Streak
+50R	8R	6
+55R	7R	6
+20R	16.5R	6
+47.5R	10.5R	6
+50R	13.5R	13
+22.5R	18R	11
+20R	13.5R	8
+10R	11.5R	7
+22.5R	9R	6
+27.5R	10.5R	7
+27.5R	11R	6
+32.5R	12.5R	11
-2.5R	26.5R	9
+42.5R	10.5R	7
+32.5R	13.5R	9
+2.5R	20.5R	8
+25R	9R	8
+35R	14R	8
+55R	8.5R	8
+17.5R	11R	7

READ THE DISTRIBUTION, NOT THE STORY

What These Paths Can Teach

The chart is a collection of possible experiences under a narrow set of assumptions. Its value comes from comparing the paths, not treating any one line as a forecast.

What this tool shows

Same inputs, different experiences

The same win rate and average outcomes can produce very different realized paths.
Positive expectancy does not mean profit on every trade or a smooth equity curve.
A probabilistic edge appears across a distribution of repeated outcomes, not within a single trade.
One short-term path is not enough to judge the value of a system.

What this tool cannot tell you

The inputs still need evidence

Whether the win rate and average R values apply to your actual strategy.
Whether your trading rules are reproducible.
Whether the inputs came from enough reliable testing.
What position size is appropriate for you.
Your future P&L or the maximum loss you may actually experience.

Generating paths is easy. The harder work is building a reproducible system that gives the inputs meaning.

NEXT STEP

The Simulator Is Only the Beginning

This simulator shows how widely profit-and-loss paths can vary even when the assumptions stay the same. But making probability work in real trading starts with a complete, repeatable system—one in which the required rules, testing process, and position sizing connect consistently from end to end.

For traders who want to turn a strategy into a system they can test, validate, and operate with their own numbers, a complete system-building blueprint is available.

View the Complete System-Building Blueprint

MODEL BOUNDARIES

A deliberately simple model

The simulator assumes independent trades with a fixed win rate, average win, and average loss. It does not include fees, slippage, changing market conditions, rule changes, or more complex outcome distributions.

PRIVACY

Your browser, your inputs

Every calculation runs only in your browser. The values you enter and the simulation results are not saved or sent. Google Analytics is used to understand how the site is used.

DISCLAIMER

Education, not advice

This tool is for educational purposes only. It is not investment advice, a profit forecast, strategy validation, or a guarantee of risk or results.