diff --git a/Algorithm/Rating/Elo.php b/Algorithm/Rating/Elo.php
index ae4b387dd..59dc9b1f7 100644
--- a/Algorithm/Rating/Elo.php
+++ b/Algorithm/Rating/Elo.php
@@ -88,9 +88,15 @@ final class Elo
      */
     public function winProbability(int $elo1, int $elo2, bool $canDraw = false) : float
     {
-        return $canDraw
-            ? -1.0 // @todo implement
-            : 1 / (1 + \pow(10, ($elo2 - $elo1) / 400));
+        $expectedWin = 1 / (1 + \pow(10, ($elo2 - $elo1) / 400));
+
+        if (!$canDraw) {
+            return $expectedWin;
+        }
+
+        $draw = $this->drawProbability($elo1, $elo2);
+
+        return (1.0 - $draw) * $expectedWin;
     }
 
     /**
@@ -105,6 +111,12 @@ final class Elo
      */
     public function drawProbability(int $elo1, int $elo2) : float
     {
-        return -1.0; // @todo implement
+        $diff = \abs($elo1 - $elo2);
+
+        // Approximate draw probability: highest when ratings are equal,
+        // decreasing smoothly as the rating difference increases.
+        $maxDraw = 0.30;
+
+        return $maxDraw * \exp(-($diff ** 2) / (2 * (200 ** 2)));
     }
 }
diff --git a/Math/Stochastic/Distribution/GeometricDistribution.php b/Math/Stochastic/Distribution/GeometricDistribution.php
index 624556be2..aeb7a9b08 100755
--- a/Math/Stochastic/Distribution/GeometricDistribution.php
+++ b/Math/Stochastic/Distribution/GeometricDistribution.php
@@ -27,6 +27,8 @@ final class GeometricDistribution
     /**
      * Constructor.
      *
+     * Example: dice roll
+     *
      * @since 1.0.0
      * @codeCoverageIgnore
      */
@@ -34,6 +36,14 @@ final class GeometricDistribution
     {
     }
 
+    /**
+     * How often to roll to get a specific value with at least percent chance
+     */
+    public static function getHowOften(float $p, float $percent) : float
+    {
+        return log(1.0 - $percent) / log(1 - $p);
+    }
+
     /**
      * Get probability mass function.
      *
diff --git a/Stdlib/Base/Heap.php b/Stdlib/Base/Heap.php
index bee427726..e23fc2ebd 100755
--- a/Stdlib/Base/Heap.php
+++ b/Stdlib/Base/Heap.php
@@ -64,7 +64,7 @@ class Heap
      *
      * @since 1.0.0
      */
-    public function insort(HeapItemInterface $x, int $lo = 0) : void
+    public function insert(HeapItemInterface $x, int $lo = 0) : void
     {
         $hi = \count($this->nodes);
 
diff --git a/tests/Ai/Ocr/Tesseract/TesseractOcrTest.php b/tests/Ai/Ocr/Tesseract/TesseractOcrTest.php
index f83c6706d..f9e3c9c47 100755
--- a/tests/Ai/Ocr/Tesseract/TesseractOcrTest.php
+++ b/tests/Ai/Ocr/Tesseract/TesseractOcrTest.php
@@ -98,7 +98,7 @@ final class TesseractOcrTest extends \PHPUnit\Framework\TestCase
      * @group framework
      */
     /*
-    @todo somehow this suddenly takes a long time.
+    this takes a long time.
     Might be because a php version update resulting in float 32->64bit changes?
     Fix it, it was working with php 8.0
     public function testOcrWithThresholdingRotating() : void