diff --git a/showcase/entries/Continuous2.re b/showcase/entries/Continuous2.re
index 86823fc0..f6cb9a53 100644
--- a/showcase/entries/Continuous2.re
+++ b/showcase/entries/Continuous2.re
@@ -19,8 +19,9 @@ let timeDist ={
 let setup = dist =>
   RenderTypes.DistPlusRenderer.make(~distPlusIngredients=dist,())
   |> DistPlusRenderer.run
-  |> RenderTypes.DistPlusRenderer.Outputs.distplus
-  |> R.O.fmapOrNull(distPlus => <DistPlusPlot distPlus />);
+  |> E.R.fmap(distPlus => <DistPlusPlot distPlus />)
+  |> E.R.toOption
+  |> E.O.toExn("")
 
 let simpleExample = (name, guesstimatorString) =>
   <>
diff --git a/showcase/entries/ExpressionTreeExamples.re b/showcase/entries/ExpressionTreeExamples.re
index ef29cdaf..2ca91990 100644
--- a/showcase/entries/ExpressionTreeExamples.re
+++ b/showcase/entries/ExpressionTreeExamples.re
@@ -1,8 +1,9 @@
 let setup = dist =>
   RenderTypes.DistPlusRenderer.make(~distPlusIngredients=dist, ())
   |> DistPlusRenderer.run
-  |> RenderTypes.DistPlusRenderer.Outputs.distplus
-  |> R.O.fmapOrNull(distPlus => <DistPlusPlot distPlus />);
+  |> E.R.fmap(distPlus => <DistPlusPlot distPlus />)
+  |> E.R.toOption
+  |> E.O.toExn("")
 
 let simpleExample = (guesstimatorString, ~problem="", ()) =>
   <>
diff --git a/src/components/DistBuilder.re b/src/components/DistBuilder.re
index 87746905..ae00fbb6 100644
--- a/src/components/DistBuilder.re
+++ b/src/components/DistBuilder.re
@@ -146,14 +146,11 @@ module DemoDist = {
                (),
              );
            let response = DistPlusRenderer.run(inputs);
-           switch (RenderTypes.DistPlusRenderer.Outputs.distplus(response)) {
-           | Some(distPlus) => {
+           switch (response) {
+           | Ok(distPlus) =>
              let normalizedDistPlus = DistPlus.T.normalize(distPlus);
-             <DistPlusPlot distPlus={normalizedDistPlus} />;
-           }
-           | _ =>
-             "Correct Guesstimator string input to show a distribution."
-             |> R.ste
+             <DistPlusPlot distPlus=normalizedDistPlus />;
+           | Error(r) => r |> R.ste
            };
          | _ =>
            "Nothing to show. Try to change the distribution description."
@@ -484,7 +481,10 @@ let make = () => {
               />
             </Col>
             <Col span=4>
-              <FieldFloat field=FormConfig.DownsampleTo label="Downsample To" />
+              <FieldFloat
+                field=FormConfig.DownsampleTo
+                label="Downsample To"
+              />
             </Col>
             <Col span=4>
               <FieldFloat field=FormConfig.KernelWidth label="Kernel Width" />
diff --git a/src/distPlus/expressionTree/ExpressionTreeEvaluator.re b/src/distPlus/expressionTree/ExpressionTreeEvaluator.re
index 134fbdbe..e93176b2 100644
--- a/src/distPlus/expressionTree/ExpressionTreeEvaluator.re
+++ b/src/distPlus/expressionTree/ExpressionTreeEvaluator.re
@@ -32,6 +32,50 @@ module AlgebraicCombination = {
        );
   };
 
+  let choose = (t1: node, t2: node) => {
+    let dLength = (r: DistTypes.discreteShape) =>
+      r.xyShape |> XYShape.T.length;
+    switch (t1, t2) {
+    | (`RenderedDist(Continuous(_)), `RenderedDist(Continuous(_))) => `Sampling
+    | (`RenderedDist(Discrete(m1)), `RenderedDist(Discrete(m2)))
+        when dLength(m1) * dLength(m2) > 1000 => `Analytical
+    | (`RenderedDist(Discrete(_)), `RenderedDist(Discrete(_))) => `Sampling
+    | (`RenderedDist(Discrete(d)), `SymbolicDist(_))
+    | (`SymbolicDist(_), `RenderedDist(Discrete(d)))
+    | (`RenderedDist(Discrete(d)), `RenderedDist(Continuous(_)))
+    | (`RenderedDist(Continuous(_)), `RenderedDist(Discrete(d))) =>
+      dLength(d) > 10 ? `Sampling : `Analytical
+    | _ => `Sampling
+    };
+  };
+  let foo =
+      (evaluationParams, algebraicOp, t1: node, t2: node)
+      : result(node, string) => {
+    E.R.merge(
+      SamplingDistribution.renderIfIsNotSamplingDistribution(
+        evaluationParams,
+        t1,
+      ),
+      SamplingDistribution.renderIfIsNotSamplingDistribution(
+        evaluationParams,
+        t2,
+      ),
+    )
+    |> E.R.bind(_, ((a, b)) =>
+         switch (choose(a, b)) {
+         | `Sampling =>
+           SamplingDistribution.combineShapesUsingSampling(
+             evaluationParams,
+             algebraicOp,
+             a,
+             b,
+           )
+         | `Analytical =>
+           combinationByRendering(evaluationParams, algebraicOp, a, b)
+         }
+       );
+  };
+
   let operationToLeaf =
       (
         evaluationParams: evaluationParams,
@@ -45,8 +89,8 @@ module AlgebraicCombination = {
     |> E.R.bind(
          _,
          fun
-         | `SymbolicDist(d) as t => Ok(t)
-         | _ => combinationByRendering(evaluationParams, algebraicOp, t1, t2),
+         | `SymbolicDist(_) as t => Ok(t)
+         | _ => foo(evaluationParams, algebraicOp, t1, t2),
        );
 };
 
diff --git a/src/distPlus/expressionTree/SamplingDistribution.re b/src/distPlus/expressionTree/SamplingDistribution.re
index 60886b40..2f95be1e 100644
--- a/src/distPlus/expressionTree/SamplingDistribution.re
+++ b/src/distPlus/expressionTree/SamplingDistribution.re
@@ -6,7 +6,7 @@ let isSamplingDistribution: node => bool =
   | `RenderedDist(_) => true
   | _ => false;
 
-let renderIfIsNotSamplingDistribution = (params, t) =>
+let renderIfIsNotSamplingDistribution = (params, t): result(node, string) =>
   !isSamplingDistribution(t)
     ? switch (Render.render(params, t)) {
       | Ok(r) => Ok(r)
@@ -70,9 +70,7 @@ let combineShapesUsingSampling =
                   },
                 ),
               )
-           |> E.O.bind(_, (r: RenderTypes.ShapeRenderer.Sampling.outputs) =>
-                r.shape
-              )
+           |> E.O.bind(_, (r) => r.shape)
            |> E.O.toResult("No response");
          shape |> E.R.fmap(r => `Normalize(`RenderedDist(r)));
        },
diff --git a/src/distPlus/renderers/DistPlusRenderer.re b/src/distPlus/renderers/DistPlusRenderer.re
index 521b244d..1d06eb4a 100644
--- a/src/distPlus/renderers/DistPlusRenderer.re
+++ b/src/distPlus/renderers/DistPlusRenderer.re
@@ -1,18 +1,4 @@
-let downsampleIfShould =
-    (
-      {recommendedLength, shouldDownsample}: RenderTypes.DistPlusRenderer.inputs,
-      outputs: RenderTypes.ShapeRenderer.Combined.outputs,
-      dist,
-    ) => {
-      let willDownsample =
-  shouldDownsample
-  && RenderTypes.ShapeRenderer.Combined.methodUsed(outputs) == `Sampling;
-    willDownsample ? dist |> DistPlus.T.downsample(recommendedLength) : dist;
-};
-
-let run =
-    (inputs: RenderTypes.DistPlusRenderer.inputs)
-    : RenderTypes.DistPlusRenderer.outputs => {
+let run = (inputs: RenderTypes.DistPlusRenderer.inputs) => {
   let toDist = shape =>
     DistPlus.make(
       ~shape,
@@ -22,7 +8,7 @@ let run =
       (),
     )
     |> DistPlus.T.normalize;
-  let outputs =
+  let output =
     ShapeRenderer.run({
       samplingInputs: inputs.samplingInputs,
       guesstimatorString: inputs.distPlusIngredients.guesstimatorString,
@@ -30,8 +16,8 @@ let run =
         length: inputs.recommendedLength,
       },
     });
-  let shape = outputs |> RenderTypes.ShapeRenderer.Combined.getShape;
-  let dist =
-    shape |> E.O.fmap(toDist) |> E.O.fmap(downsampleIfShould(inputs, outputs));
-  RenderTypes.DistPlusRenderer.Outputs.make(outputs, dist);
+  output
+  |> E.R.fmap((o: RenderTypes.ShapeRenderer.Symbolic.outputs) =>
+       toDist(o.shape)
+     );
 };
diff --git a/src/distPlus/renderers/ShapeRenderer.re b/src/distPlus/renderers/ShapeRenderer.re
index a54c8c34..bc6bf411 100644
--- a/src/distPlus/renderers/ShapeRenderer.re
+++ b/src/distPlus/renderers/ShapeRenderer.re
@@ -36,9 +36,6 @@ let runSymbolic = (inputs: RenderTypes.ShapeRenderer.Combined.inputs) => {
      );
 };
 
-let run =
-    (inputs: RenderTypes.ShapeRenderer.Combined.inputs)
-    : RenderTypes.ShapeRenderer.Combined.outputs => {
-  let symbolic = runSymbolic(inputs);
-  {symbolic: Some(symbolic), sampling: None};
+let run = (inputs: RenderTypes.ShapeRenderer.Combined.inputs) => {
+  runSymbolic(inputs);
 };
diff --git a/src/distPlus/renderers/samplesRenderer/Samples.re b/src/distPlus/renderers/samplesRenderer/Samples.re
index ff8f6f46..7f9b10aa 100644
--- a/src/distPlus/renderers/samplesRenderer/Samples.re
+++ b/src/distPlus/renderers/samplesRenderer/Samples.re
@@ -1,3 +1,42 @@
+module Types = {
+  let defaultSampleCount = 5000;
+  let defaultOutputXYPoints = 10000;
+
+  type inputs = {
+    sampleCount: option(int),
+    outputXYPoints: option(int),
+    kernelWidth: option(float),
+  };
+
+  type samplingStats = {
+    sampleCount: int,
+    outputXYPoints: int,
+    bandwidthXSuggested: float,
+    bandwidthUnitSuggested: float,
+    bandwidthXImplemented: float,
+    bandwidthUnitImplemented: float,
+  };
+
+  type outputs = {
+    continuousParseParams: option(samplingStats),
+    shape: option(DistTypes.shape),
+  };
+
+  let empty = {sampleCount: None, outputXYPoints: None, kernelWidth: None};
+
+  type fInputs = {
+    sampleCount: int,
+    outputXYPoints: int,
+    kernelWidth: option(float),
+  };
+
+  let toF = (i: inputs): fInputs => {
+    sampleCount: i.sampleCount |> E.O.default(defaultSampleCount),
+    outputXYPoints: i.outputXYPoints |> E.O.default(defaultOutputXYPoints),
+    kernelWidth: i.kernelWidth,
+  };
+};
+
 module JS = {
   [@bs.deriving abstract]
   type distJs = {
@@ -21,39 +60,6 @@ module KDE = {
     |> JS.samplesToContinuousPdf(_, outputXYPoints, kernelWidth)
     |> JS.jsToDist;
   };
-
-  // Note: This was an experiment, but it didn't actually work that well.
-  let inGroups = (samples, outputXYPoints, kernelWidth, ~cuttoff=0.9, ()) => {
-    let partitionAt =
-      samples
-      |> E.A.length
-      |> float_of_int
-      |> (e => e *. cuttoff)
-      |> int_of_float;
-    let part1XYPoints =
-      outputXYPoints |> float_of_int |> (e => e *. cuttoff) |> int_of_float;
-    let part2XYPoints = outputXYPoints - part1XYPoints |> Js.Math.max_int(30);
-    let part1Data =
-      samples |> Belt.Array.slice(_, ~offset=0, ~len=partitionAt);
-    let part2DataLength = (samples |> E.A.length) - partitionAt;
-    let part2Data =
-      samples
-      |> Belt.Array.slice(
-           _,
-           ~offset=(-1) * part2DataLength,
-           ~len=part2DataLength,
-         );
-    let part1 =
-      part1Data
-      |> JS.samplesToContinuousPdf(_, part1XYPoints, kernelWidth)
-      |> JS.jsToDist;
-    let part2 =
-      part2Data
-      |> JS.samplesToContinuousPdf(_, part2XYPoints, 3)
-      |> JS.jsToDist;
-    let opp = 1.0 -. cuttoff;
-    part1;
-  };
 };
 
 module T = {
@@ -109,7 +115,7 @@ module T = {
   let toShape =
       (
         ~samples: t,
-        ~samplingInputs: RenderTypes.ShapeRenderer.Sampling.Inputs.fInputs,
+        ~samplingInputs: Types.fInputs,
         (),
       ) => {
     Array.fast_sort(compare, samples);
@@ -126,6 +132,7 @@ module T = {
       continuousPart |> E.A.length > 5
         ? {
           let _suggestedXWidth = Bandwidth.nrd0(continuousPart);
+          // todo: This does some recalculating from the last step.
           let _suggestedUnitWidth =
             suggestedUnitWidth(continuousPart, samplingInputs.outputXYPoints);
           let usedWidth =
@@ -136,7 +143,7 @@ module T = {
               samplingInputs.outputXYPoints,
               usedWidth,
             );
-          let foo: RenderTypes.ShapeRenderer.Sampling.samplingStats = {
+          let foo: Types.samplingStats = {
             sampleCount: samplingInputs.sampleCount,
             outputXYPoints: samplingInputs.outputXYPoints,
             bandwidthXSuggested: _suggestedXWidth,
@@ -159,7 +166,7 @@ module T = {
         ~continuous=pdf |> E.O.fmap(fst),
         ~discrete=Some(discrete),
       );
-    let samplesParse: RenderTypes.ShapeRenderer.Sampling.outputs = {
+    let samplesParse: Types.outputs = {
       continuousParseParams: pdf |> E.O.fmap(snd),
       shape,
     };
@@ -168,11 +175,11 @@ module T = {
 
   let fromSamples =
       (
-        ~samplingInputs=RenderTypes.ShapeRenderer.Sampling.Inputs.empty,
+        ~samplingInputs=Types.empty,
         samples,
       ) => {
     let samplingInputs =
-      RenderTypes.ShapeRenderer.Sampling.Inputs.toF(samplingInputs);
+      Types.toF(samplingInputs);
     toShape(~samples, ~samplingInputs, ());
   };
 };
diff --git a/src/interface/FormBuilder.re b/src/interface/FormBuilder.re
index 7556a82f..ea06e318 100644
--- a/src/interface/FormBuilder.re
+++ b/src/interface/FormBuilder.re
@@ -25,11 +25,9 @@ let propValue = (t: Prop.Value.t) => {
         ~shouldDownsample=true,
         (),
       )
-      |> DistPlusRenderer.run
-      |> RenderTypes.DistPlusRenderer.Outputs.distplus;
+      |> DistPlusRenderer.run;
     switch (newDistribution) {
-    | Some(distribution) =>
-      <div> <DistPlusPlot distPlus=distribution /> </div>
+    | Ok(distribution) => <div> <DistPlusPlot distPlus=distribution /> </div>
     // <input
     //   readOnly=true
     //   className="shadow appearance-none border w-1/3 rounded py-2 px-3 text-gray-700 leading-tight focus:outline-none focus:shadow-outline"
@@ -45,7 +43,7 @@ let propValue = (t: Prop.Value.t) => {
     //   className="w-1/3 border w-1/2 rounded py-2 px-3 text-gray-700 leading-tight focus:outline-none focus:shadow-outline bg-white">
     //   {"30 to infinity, 80% mass" |> ReasonReact.string}
     // </div>
-    | None => "Something went wrong" |> ReasonReact.string
+    | Error(e) => e |> ReasonReact.string
     };
   | FloatCdf(_) => <div />
   | Probability(r) =>
diff --git a/src/models/EAFunds.re b/src/models/EAFunds.re
index 65f26ef9..215bfe2a 100644
--- a/src/models/EAFunds.re
+++ b/src/models/EAFunds.re
@@ -112,8 +112,12 @@ module Model = {
     GlobalCatastrophe.makeI(MomentRe.momentNow())
     |> RenderTypes.DistPlusRenderer.make(~distPlusIngredients=_, ())
     |> DistPlusRenderer.run
-    |> RenderTypes.DistPlusRenderer.Outputs.distplus
-    |> E.O.bind(_, DistPlusTime.Integral.xToY(Time(dateTime)));
+    |> E.R.bind(_, r =>
+         r
+         |> DistPlusTime.Integral.xToY(Time(dateTime))
+         |> E.O.toResult("error")
+       )
+    |> E.R.toOption;
   };
 
   let make =
@@ -299,4 +303,4 @@ module Interface = {
       outputTypes: [||],
       run,
     };
-};
\ No newline at end of file
+};