diff --git a/lib/strategies/base.js b/lib/strategies/base.js
index a974915..45c5114 100644
--- a/lib/strategies/base.js
+++ b/lib/strategies/base.js
@@ -2,21 +2,26 @@
  * Base strategy class. All strategies extend this.
  * 
  * Strategies receive market state updates and emit trade signals.
- * Signals are { side: 'yes'|'no', price: number, size: number, reason: string }
+ * Signals are { side: 'yes'|'no', price: number, maxPrice: number, size: number, reason: string }
+ * 
+ * `price` = ideal/target price in cents
+ * `maxPrice` = maximum acceptable fill price (slippage tolerance)
  */
 export class BaseStrategy {
   constructor(name, config = {}) {
     this.name = name;
     this.config = config;
     this.enabled = true;
-    this.mode = 'paper'; // 'paper' | 'live'
+    this.mode = 'paper';
   }
 
   /**
    * Called on every market state update.
+   * @param {object} marketState - includes yesPct, noPct, orderbook, ticker, closeTime, etc.
+   * @param {string} caller - 'paper' | 'live' — so strategies can track per-caller state
    * Return a signal object or null.
    */
-  evaluate(marketState) {
+  evaluate(marketState, caller = 'paper') {
     throw new Error(`${this.name}: evaluate() not implemented`);
   }